biennial radiotherapy error data analysis and learning report · biennial radiotherapy error data...
TRANSCRIPT
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
Report No. 6
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
2
About Public Health England
Public Health England exists to protect and improve the nation’s health and wellbeing
and reduce health inequalities. We do this through world-leading science, research,
knowledge and intelligence, advocacy, partnerships and the delivery of specialist public
health services. We are an executive agency of the Department of Health and Social
Care, and a distinct delivery organisation with operational autonomy. We provide
government, local government, the NHS, Parliament, industry and the public with
evidence-based professional, scientific and delivery expertise and support.
Public Health England
Wellington House
133-155 Waterloo Road
London SE1 8UG
Tel: 020 7654 8000
www.gov.uk/phe
Twitter: @PHE_uk
Facebook: www.facebook.com/PublicHealthEngland
© Crown copyright 2020
You may re-use this information (excluding logos) free of charge in any format or
medium, under the terms of the Open Government Licence v3.0. To view this licence,
visit OGL. Where we have identified any third-party copyright information you will need
to obtain permission from the copyright holders concerned.
Published June 2020
PHE publications PHE supports the UN
gateway number GW-1330 Sustainable Development Goals
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
3
Contents
About Public Health England 2
Executive summary 4
References 7
1. Introduction 8
2. Background 9
3. Data 10
3.1 Obtaining the data 10 3.2 Number of reports 11 3.3 Lag time for reporting 13
3.4 Quality assurance of the data 13
4. Results 15
4.1 Main themes of RTE 15 4.2 Classification level of RTE 18
4.3 Breakdown of classification by process subcode 19 4.4 Safety barriers 28
4.5 Causative factors 32 4.6 Brachytherapy RTE 37
4.7 Inspectorate data 41
5. Discussion 47
5.1 Increase in RTE reporting 47
5.2 Main themes 49 5.3 Classification level of RTE 50
5.4 Safety barriers 53 5.5 Causative factors 53 5.6 Brachytherapy RTE 54 5.7 Inspectorate data 54
6. Conclusion 56
7. Recommendations 58
8. Acknowledgements and PSRT Steering Group membership 59
Acknowledgements 59
9. References 60
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
4
Executive summary
The fundamental role of reporting and learning systems is to enhance patient safety by
learning from failures of the healthcare system(1). The value of near miss and error
reporting and learning processes is well appreciated in the UK radiotherapy (RT)
community with 100% of NHS RT providers subscribing to a national voluntary system
of reporting of RT error and near miss events.
This report is the sixth in a series of two-year reports(2), providing an overview of
Radiotherapy Error (RTE) data reported voluntarily to the National Reporting and
Learning System (NRLS) and directly to PHE between January 2018 and December
2019. The report also contains aggregate data from January 2010 to December 2019
and compares data with that from preceding 2-year periods. This report also contains
data received from the inspectorates for IR(ME)R for England, Wales, Northern Ireland
and Scotland. The analysis undertaken uses the taxonomies from ‘Towards Safer
Radiotherapy’(3) and the ‘Development of Learning from RTE’(4), thus facilitating
comparisons of national RTE trends with both local and network findings.
A total of 18,734 RTE reports were included in this analysis from 98.3% of UK RT
providers. An estimated reported RTE rate of 4 per 1,000 attendances or 45 per 1,000
prescriptions was calculated. An estimated report RTE rate for level-one events was
calculated as 0.4 per 1,000 prescriptions. It is worth noting that the clear majority of
these events did not impact on the patients’ planning, treatment or outcome.
Consistent with previous reports(2) RTE were spread across all 21 categories of
process codes; treatment unit process codes were the most frequently reported RTE
(42.3%, n = 7,923). The most frequently reported process subcode was ‘on-set
imaging: production process’, making up 12.3% (n = 2,310) of all RTE reported.
Of the RTE reports, 62.3% (n = 11,679) were ‘near miss’ or ‘other non-conformances’
with no impact on patient outcome. In total, 35.9% (n = 6,724) of the RTE reported
were not clinically significant and were classified as ‘minor radiation incidents’. Of the
remaining 1.8% (n = 331) RTE reports only 0.9% were reportable. When compared
with the results from the previous two-year report there has been a reduction in the
percentage of reportable radiation incidents from 1.0% to 0.9%.
Safety barriers (SB) are embedded across the RT pathway coding. The SB taxonomy
can be used to separately identify both failed and effective SB. Treatment process ‘use
of on-set imaging’ was the most frequently reported failed SB (10.5%, n = 1,392). For
this reporting period, the most frequently reported effective SB was ‘on-set imaging:
approval process’ (22.9%, n = 872). The use of a causative factor taxonomy enables
identification of system problems that could precipitate a range of different incidents.
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
5
From the RTE which contained a root cause (RC), the most frequently reported was
individual ‘slips and lapses’, making up 43.8% (n = 8,058) of all RC. The most
frequently reported contributory factor was ‘adherence to procedures/protocols’ (41.5%,
n = 2,534).
Consistent with findings in the literature, there are a small number of significant
incidents and a greater number of lower level incidents. The proportion of significant
incidents has continued to decrease slightly since the previous two-year period.
On-set imaging associated RTE made up a significant proportion of all reported RTE.
This reflects the increase in automation of processes across the radiotherapy pathway.
On-set imaging processes now represent a focal point for decision making processes
on the pathway and are the last point on the pathway prior to initiating treatment
exposures. The most frequently reported root cause of RTE was individual ‘slips and
lapses’. This is reflected in the level of data and image interpretation required as part of
imaging processes. The risk of error in imaging processes may be amplified due to the
dynamic nature of online review and the rapid pace of development of new
technologies and techniques, together with an increase in imaging frequency. However,
the benefit image-guided RT brings to the patient is clear as it is frequently associated
with error detection methods and as such image guided RT (IGRT) remains a critical
safety barrier in RT.
Outputs from RTE analysis should be used to inform prospective risk assessments in
thematic areas identified in the analysis as part of a study of the risk of accidental and
unintended exposures to further mitigate against these types of RTE. This approach
supports compliance with regulation 8(2) and 8(3) of the Ionising Radiation (Medical
Exposure) Regulations (IR(ME)R) requires the recording analyses of events or
potentially involving accidental or unintended exposures (5,6).
RT is ever evolving with new techniques and technology. Therefore, these trends
should continue to be reported and learnt from. The move to increased hypo-
fractionation of external beam RT will reduce the opportunities to correct for RTE. The
role of reporting and learning systems will continue to play a part in helping identify and
address RTE.
This work supports a risk-based approach to improving safety both locally, regionally
and nationally and indicates a culture that is open, transparent and already present in
the UK RT community.
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
6
Local provider recommendations are that:
• all UK RT providers should continue to use ‘Towards Safer Radiotherapy’(3) and
‘Development of Learning’(4) taxonomies to code all levels of RTE for local analysis to
inform local learning and practice
• UK NHS RT providers should continue to submit fully coded RTE reports, of all levels, to
the national voluntary reporting system using the mechanisms identified within this report,
monthly, to ensure timeliness of shared learning
• adherence to protocols / procedures and slips and lapses are the most frequently reported
causative factors. RT providers should consider working arrangements associated with
these reports
• consideration should be given to introducing a ‘pause and check’ policy for on-line image
capture, review and approval to reduce IGRT associated RTE
• a review of referral guidelines and procedures should be undertaken to ensure all required
diagnostic information is in place prior to justification and authorisation of treatment and
made available to inform planning processes to minimise the risk of a missed verification of
diagnosis / staging of disease
• consideration should be given to reviewing the effectiveness and timing of ‘end of process
checks’ to ensure they are optimal in the pathway to mitigate RTE
• local learning should be compared with the national picture and used to inform local and
network level practice
• independent providers should consider submitting RTE to the national voluntary reporting
system
• RTE analysis should be used to inform prospective risk assessments as part of a study of
the risk of accidental and unintended exposures to support compliance with IR(ME)R
(Regulation 8(2) and 8(3))
National recommendations are that:
• PSRT should continue to develop the national analysis and learning from RTE, with timely
dissemination of findings to the RT community for wider learning
• RTE should be used by the PSRT and individual RT providers as part of a risk-based
approach to allocating resources for improving patient safety in radiotherapy and to inform
audit and research
• PSRT should engage vendors in developments to reduce the rate of RTE related to
equipment failure and human factors.
• in areas demonstrating an initial increase in RTE that are then seen to fall, Learning from
Excellence may be useful. PSRT should develop RT based tools to support the
implementation of emerging patient safety theory
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
7
References
1. World Health Organization. Reporting and learning for patient safety. Available at https://www.who.int/patientsafety/implementation/reporting_and_learning/en/
2. PSRT. Radiotherapy errors and near misses: biennial report. Nos 1-5. Available at www.gov.uk/government/publications/radiotherapy-errors-and-near-misses-data-report
3. RCR, SCoR, IPEM, NPSA, BIR. Towards Safer Radiotherapy. Royal College of Radiologists, London (2008). Available at www.rcr.ac.uk/towards-safer-radiotherapy
4. PSRT. Development of learning from radiotherapy errors. Available at www.gov.uk/government/publications/development-of-learning-from-radiotherapy-errors
5 The Ionising Radiation (Medical Exposure) Regulations 2017. The Stationery Office, London, SI 2017/1322.www.legislation.gov.uk/uksi/2017/1322/contents/made.
6 The Ionising Radiation (Medical Exposure) Regulations (Northern Ireland) 2018. The Stationery Office, London, SR 2018/17. www.legislation.gov.uk/nisr/2018/17/contents/made.
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
8
1. Introduction
Patient safety in radiotherapy (RT) has been defined as the absence of an
unacceptable risk of harm when harm is excessive morbidity or sub-optimal tumour
control(1). A strong safety culture is a cornerstone of patient safety and is essential in
ensuring the risk of probability and magnitude of error are minimised. A reporting and
learning system contributes to an effective safety culture(2). It is imperative errors and
near misses are learned from and effective preventative measures are implemented(3).
The fundamental role of reporting and learning reporting systems is to enhance patient
safety by learning from failures of the healthcare system(4). It is known that most
problems are not just a series of random, unconnected one-off events; they are
provoked by weaknesses in systems and processes and often have common root
causes which can be generalised and corrected. Although each event is unique, there
are likely to be similarities and patterns in sources of risk that may go unnoticed if
incidents are not reported and analysed. To maintain or improve patient safety, errors
must be prevented or minimised by such reporting and analysis.
Experience has shown that as an organisation’s reporting culture matures, staff
become more likely to report radiotherapy error and near miss events (RTE). There is
an emerging evidence base that organisations with a higher rate of reporting have a
stronger safety culture(5). All RT providers should have clear guidelines in their quality
system on error management, and actions to be taken when errors occur.
The 2006(6) report of the Chief Medical Officer for England and Towards Safer
Radiotherapy (TSRT), published in 2008(7), were seminal documents in the field of RT
safety; both contained practical recommendations for the RT community aimed at
improving safety and reducing errors. These recommendations have been adopted by
UK RT providers. In 2016, the Development of Learning (DoL) from Radiotherapy
Errors(8), a guidance document supporting the enhancement of learning from RTE and
their analysis, was published. These key publications have facilitated the national
sharing of RTE.
This report is the sixth in a series of two-year reports(9), providing an overview of RTE
data reported voluntarily to the National Reporting and Learning System (NRLS)(10) and
directly to PHE between January 2018 and December 2019. The report also contains
aggregate data from January 2010 to December 2019.
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
9
2. Background
This analysis has been undertaken by Public Health England (PHE) on RTE reported
voluntarily by NHS RT providers and the relevant enforcing authorities for the Ionising
Radiation (Medical Exposure) Regulations (IR(ME)R). The analysis has been reviewed
by the Patient Safety in Radiotherapy Steering Group (PSRT). This multidisciplinary
group's membership includes a patient representative alongside representatives from
the Institute of Physics and Engineering in Medicine (IPEM), Royal College of
Radiologists (RCR), Society and College of Radiographers (SCoR) and PHE. The
PSRT are tasked with leading a collaborative programme of work to improve patient
safety in RT.
TSRT(7) provides definitions for the terminology to be used in defining RT errors that
include near misses (RTE) and proposed 2 taxonomies for use in describing RTE. The
‘Classification of radiotherapy errors grid’ describes the severity of the error and the
‘Radiotherapy pathway coding’ describes where in the RT pathway the error occurred.
In December 2016, a guidance document containing the refinement of the
‘Radiotherapy pathway coding’ to include ‘Safety barriers’ (SB) and a proposed
‘Causative factor (CF) taxonomy’ was published(8). The document also contains
definitions and examples on the application of the taxonomies.
It has been stated that a critical safety feature of an organisation is how it learns from
its own and from others’ experience(3). The value of near miss and error reporting and
learning processes is well appreciated in the UK RT community with 100% of NHS RT
providers subscribing to a system of national voluntary reporting of RT error and near
miss events. The PSRT recommends learning from this analysis and the tri-annual
analyses(11). These publications facilitate the comparison of locally identified trends
against the national picture.
The National Reporting and Learning System (NRLS) is an anonymised voluntary
reporting system to collect and learn from patient safety incidents for England and
Wales. The NRLS is managed by the Patient Safety Team who currently sit within NHS
England and Improvement (NHSEI). PHE has a data sharing agreement with the NRLS
and under this agreement RTE data is extracted from the NRLS and shared with PHE
for analysis to support learning from these events with the principle aim of making
services safer for patients.
This collaboration led to the publication in July 2010(9) of the first two-year report on a
back catalogue of patient safety incidents reported to the NRLS between August 2007
and November 2009. In November 2013, a mechanism for providers in Northern
Ireland and Scotland to contribute to this voluntary reporting scheme was introduced.
Subsequently, data from across the UK, including data received from the relevant
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
10
enforcing authorities for IR(M)ER for England, Wales, Northern Ireland and Scotland
was published in subsequent two-year reports(9). The relevant enforcing authorities will
be referred to as inspectorates here after. The fifth report included analysis using the
new taxonomies(8) including the refined pathway coding, safety barrier and causative
factor taxonomies. This sixth report also contains analysis of the method of detection of
taxonomies.
3. Data
The data presented in this report is anonymised and received as part of a voluntary
reporting scheme. As with any voluntary reporting system, the data will only reflect
those incidents that are reported and may not necessarily be representative of the
actual levels of error occurrence, as such, this data requires interpreting with care.
Data for the reporting period January 2018 to December 2019 forms the focus for the
analysis. Where possible, comparisons are drawn against data for two-yearly reporting
periods going back over 10 years. This report includes data from January 2010 to
December 2019.
3.1 Obtaining the data
The voluntary data was obtained through 3 distinct routes: from the NRLS in England and
Wales and directly from providers in Northern Ireland and Scotland. These routes are
described in detail below. In addition, anonymised synopsis of closed reportable radiation
incidents was shared by the IR(ME)R inspectorates for England, Northern Ireland, Scotland
and Wales with PHE for inclusion in the analysis.
3.1.1 National voluntary reporting system
The vast majority of reports came through the NRLS(10) at NHSEI for providers, which
collates reports for England and Wales. The NRLS operates a voluntary reporting
system to collect and learn from patient safety incidents. A patient safety incident (PSI)
is defined as:
‘Any unintended or unexpected incident which could have, or did, lead to harm for one
or more patients receiving healthcare’(10).
PSIs are primarily reported by NHS organisations in England and Wales through bulk
upload via local trust risk management systems to the NRLS. Independent providers
are also able to report to the NRLS using web-based forms. Both healthcare staff and
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
11
the general public are encouraged to report any incidents directly through an open
access form(12). The NRLS offers a unique dataset to help understand harm associated
with healthcare. It was established in 2003 and now has almost 22 million PSI
reports(13), from many areas of healthcare, in the database.
The NRLS can be interrogated for relevant incidents by searching the free text field of
any incident report using keywords or search terms. During the development of this
work, a system was created to extract targeted data from the NRLS using a trigger
code ‘TSRT9’. This was proposed and described in ‘Implementing Towards Safer
Radiotherapy: guidance on reporting RTE effectively’(14). This code is searched for in
the free text field rather than using search terms that were found to be less
determinant. A RTE is defined in TSRT as:
‘a non-conformance where there is an unintended divergence between a RT treatment
delivered or a RT process followed and that defined as correct by local protocol’(7).
PSIs that are not RTE, such as a report of a patient falling in a RT department, are not
included in the RTE dataset. These are reviewed, analysed and shared by NHSEI. The
NRLS is now under redevelopment as part of the patient safety incident management
systems (PSIMS) project(13), where the new system will support more learning
opportunities, so the NHS can continue to improve safety.
3.1 2 Northern Ireland and Scotland
A mechanism was developed to enable providers in Northern Ireland and Scotland to
participate in this scheme in 2013. Once agreements for data sharing were achieved
with health boards and hospital trusts, predefined criteria consistent with those
employed for the NRLS data were shared with RT providers in Northern Ireland and
Scotland for inclusion in reports.
Anonymised data has been accepted from providers on Microsoft® Office Excel
spreadsheets for direct upload into the PHE RTE incident database to minimise the
possibility of transcription error and to ensure the anonymity of the data. PHE is
working with the NRLS to further streamline the reporting mechanism for providers in
Northern Ireland and Scotland.
3.2 Number of reports
A total of 18,853 RTE reports were submitted to the voluntary reporting scheme
between January 2018 and December 2019, with an average 786 reports per month.
There has been an increase in reporting since the previous two-year reporting period,
where a total of 16,308 RTE reports were submitted between January 2016 and
December 2017, with an average 680 reports per month. Figure 1 indicates a peak in
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
12
reporting in May and October. The peaks in October and May correlates with the 6
monthly NRLS reporting deadline for their annual reports(12). This variation highlights
that not all providers report monthly.
Figure 1. Average number of RTE reports submitted to the national voluntary reporting system by month (January 2010 to December 2019)
Due to the merging of 2 providers there are now 60 NHS providers across the UK. For
this two-year period, reports were received from the clear majority of NHS RT
providers, 59 (98.3%). This is the same as the previous two-year period where 59 out
of 61 NHS providers reported to the national analysis.
There is some variance in the number of reports submitted by provider. One provider
reported 1,450 RTE across all levels of RTE and 65.0% (n = 39) providers reported
less than the average of 312 RTE over the two-year period (Figure 2). It should be
noted that there is also variation in the numbers of treatments delivered between small,
medium and large providers.
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
13
Figure 2. Number of RTE reported by provider (January 2018 to December 2019, n = 18,734, average =213)
It should be noted that those providers reporting higher numbers of RTE represent
providers with mature reporting cultures and should be encouraged to continue
reporting. A 2018 survey(15) of RT providers, showed providers were less likely to
submit level 5 RTE nationally where dual local reporting and learning systems were in
operation as to do so would require additional resource.
3.3 Lag time for reporting
A lag time between the date of the RTE and the date on which it was reported to the
NRLS or PHE was calculated for each report included in the dataset. This measures
the time from date of RTE discovery to date shared with PHE. A minimum reporting lag
of 0 days and a maximum 658 days was found for individual RTE. There was an
average lag time of 51 days and a mode of 21 days across providers. This is similar to
findings at the NRLS(16). This average lag time is also similar to that found in the
previous two-year analysis, where the average lag time was 48 days. The maximum lag
time has reduced from 871 days which indicates there are fewer outliers reporting with
extended lag times. A total of 27 reports were received with a lag time of over 500
days. Of these, 59.3% (n = 16) were reported from a single provider as part of a bulk
upload. There was no obvious explanation for the delay in reporting these 27 RTE.
3.4 Quality assurance of the data
All providers were asked to include a trigger code, classification(7), pathway coding,
including failed safety barriers, causative factor and, where applicable, effective safety
barriers (methods of detection)(8) in RTE reports to facilitate both local and national
analysis.
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
14
On receipt of the reports, PHE staff with clinical RT expertise performed consistency
checking of the local application of the classification and coding. The coding was
reviewed for all RTE classified as reportable through to near miss (levels 1-4) and 10%
of non-conformances (level 5) RTE were audited. This formed part of the data quality
assurance process completed prior to analysis of the reports.
Reports were categorised into complete, incomplete or non-RTE. Complete reports
contain the classification and pathway coding, complete fixed reports are defined as
complete reports which have had the classification, and/or the pathway coding,
amended for consistency reasons. Further guidance is available on the application of
the classification, pathway and causative factor coding(8). Incomplete reports are
defined as reports without the classification and coding being applied locally prior to
submission, incomplete fixed reports are reports which had sufficient text descriptors to
assign the classification and/or pathway coding. In April 2018, the definition of a
complete report was changed to include reports with classification, pathway coding and
causative factor taxonomy to reflect the introduction of the new taxonomies. This is
displayed in figure 3, representing data for January to March 2018 (n = 1,954) and April
2018 to December 2019 (16,899) respectively.
Of the 18,853 RTE reports received, a total of 18,734 reports were included in the
analysis, 15,358 had been classified and coded by local RT providers (1,817 between
January and March 2018 and 13,541 between April 2018 and December 2019, Figure
3).
Figure 3. Breakdown of report QA (January to March 2018, n = 1,954 and April 2018 to December 2019, n = 16,899)
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
15
There were 127 incomplete reports between January and March 2018 and 3,250
between April 2018 and December 2019, only one of which did not contain sufficient
information to assign classification and coding. The remaining 118 non-RTE or PSI
reports, were excluded from the analysis. A total of 99.4% (81.5% complete and 17.9%
incomplete) of the data submitted was included for analysis in this report, this is
consistent with reported data in 2018(9). The number of complete reports fully coded,
submitted for analysis continues to increase as providers have adopted the new
taxonomies and adjusted to the new reporting requirements as feedback via the ‘Safer
Radiotherapy’ newsletter series(15).
4. Results
4.1 Main themes of RTE
The 18,734 RTE reports were categorised by classification(7), process code or process
subcode including failed and effective safety barriers and causative factors(8), so main
themes could be derived.
The data analysis has been presented using graphs, bar charts and pie charts to
facilitate local replication of the analysis using local data to enable data comparison.
Statistical tests were carried out using Stata® Software to look for differences and
emerging trends within the data. The test for proportions was based on Z-test statistics
and the test for trends was based on Chi2 test statistics.
4.1.1 Breakdown of process codes
The entire dataset was broken down by process code and classification level. RTE
reports were spread across all 21 categories of process code and level. The RTE
reported associated with ‘treatment unit process’ comprised 42.3% (n = 7,923) of the
data and ‘pretreatment planning process’ 14.7% (n = 2,763) (Figure 4).
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
16
Figure 4. Breakdown of RTE process code by level (January 2018 to December 2019, 17,343/ 18,734 subset of RTE)
‘Treatment unit process’ process code reports were made up of ‘minor radiation
incidents’ (level 3) at 69.8% (n = 5,331), ‘near misses’ (level 4) at 16.6% (n = 1,318)
and ‘other non-conformance’ (level 5) at 14.1% (n =1,116). The remaining 2.0% (n =
158) of ‘treatment unit processes’ process code reports were ‘non-reportable radiation
incidents’ (level 2) and ‘reportable radiation incidents’ (level 1).
There have been few changes across the most frequently reported RTE process
codes. The main change to note is the decrease in ‘treatment data entry process’ which
has decreased from 7.1% in the previous two-year period to 6.0% for this two-year
period, which was statistically significant (p < 0.001). However, this reduction seems
less significant when compared with previous two-year datasets as shown in figure 5
(slope = −0.3%, p = 0.0002).
Figure 5 indicates a slight decrease in reported RTE associated with the ‘pretreatment
planning process’ (slope = −1.1%, p > 0.001) since January 2010. The largest increase
can be seen in RTE associated within the ‘treatment unit process’ (slope = 2.4%, p >
0.001).
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
17
Figure 5. Trends for most frequently reported RTE by process code (January 2010 to December 2019)
4.1.2 Breakdown of process subcodes
The most frequently reported process subcode was ‘on-set imaging: production
process’, making up 12.3% (n = 2,310) of all RTE reported. This was followed by ‘on-
set imaging’ at 4.4% (n = 824) and ‘documentation of instructions/information’ at 4.3%
(n = 803). The most frequently reported subcodes and their classification level are
presented in figure 6. Most of the ‘on-set imaging: production process’ RTE were
classified as ‘minor radiation incidents’ (level 3) at 92.9% (n = 2,145).
Figure 6. Breakdown of RTE process subcodes by level (January 2018 to December 2019 (7,941/ 18,734 subset of RTE)
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
18
The process subcodes were reviewed against the previous two-year period as shown
in figure 7. There has been a slight increase from 11.6% in the previous two-year
reporting period to 12.3% within this two-year reporting period (p = 0.045) for reports
associated with the subcode ‘on-set imaging: production process’. Other imaging
associated RTE which have also increased, include ‘use of on-set imaging’ and ‘on-set
imaging: recording. There has been a decrease in RTE associated with ‘accuracy of
data entry’, from 5.1% to 4.1% (p < 0.001). This was the most frequently reported RTE
in the reporting January 2010 to December 2012.
Figure 7 indicates the subcode ‘on-set imaging: production process’ has had the
biggest and most statistically significant increase (p < 0.001) since the 2 years of
January 2010 to December 2011; from 3.2% to 12.3% in this reporting period (slope =
2.4%, p < 0.001). The trend of RTE associated with ‘use of on-set imaging’ has
increased from 1.9% in the first two-year reporting period to 4.4% for this reporting
period (p < 0.001). This peaked in the two-year reporting period January 2014 to
December 2015 (slope = −0.45%, p < 0.001).
Figure 7. Trends for most frequently reported RTE process subcodes (January 2010 to December 2019)
4.2 Classification level of RTE
Each of the reports were classified as ‘other non-conformances’ (level 5), ‘near miss’
(level 4), ‘minor radiation incident’(level 3), ‘non-reportable radiation incident’ (level 2)
and ‘reportable radiation incident’ (level 1)(7). Figure 8 includes data for this two-year
period, the previous two-year period and aggregate data (Jan 2010 – Dec 2019).
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
19
Of the RTE reports, 62.3% (n = 11,679) were ‘near miss’ or ‘other non-conformances’
with no impact on patient outcome. In total, 35.9% (n = 6,724) of the RTE reported
were classified as ‘minor radiation incidents’. Of the remaining 1.8% (n = 331) of RTE
reports only 0.9% were reportable under IR(ME)R (7, 17, 18), to the relevant inspectorate.
This is similar to the previous two-year period, when the ‘reportable radiation incidents’
were 1.0% (n = 161, p = 0.336). The ‘non-reportable radiation incidents’ have reduced
from 1.4% (n = 221) during the previous two-year period to 0.9% (n = 64, p < 0.001).
There has also been a decrease in percentage of ‘other non-conformances’ from
40.4% (n = 4,095) within the previous two-year period to 37.9% (n = 7,102, p < 0.001).
The only increase was seen in the ‘minor radiation incidents’ which has increased from
31.9% to 35.9% (p < 0.001).
Figure 8. Classification levels as a percentage of RTE reports (January 2010 to December 2019)
4.3 Breakdown of classification by process subcode
In this section, the RTE reports are broken down by classification into their attributed
process subcodes.
4.3.1 Breakdown of level 1 (reportable radiation incident) RTE
‘Reportable radiation incidents’ (level 1) as defined in TSRT(7) fall into the category of
reportable under IR(ME)R(7, 17, 18). Clearly, reporting to the national voluntary reporting
scheme does not negate regulatory requirements to report events to the relevant
inspectorate. The majority of level 1 events reported affected only a single fraction of
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
20
treatment and thus were correctable over the remaining fractions with no significant
impact on the patient or outcome of treatment.
There were 52 different subcodes associated with the 167 level 1 RTE (Figure 9).
These were reported by 49 of the 59 providers that submitted data for analysis. The
most frequently reported subcode was ‘on-set imaging: approval process’ comprising
12.5% (n = 21) of all level 1 reports. An example of this type of reportable RTE includes
the mismatch of vertebral level during verification image review and approval leading to
a geographical miss.
Figure 9. Breakdown of most frequently reported level 1 RTE (Jan 18 - Dec 19, n = 98/ 167 subset of RTE)
The most statistically significant change in this level of RTE is the increase in ‘on-set
imaging: production process’ which has increased from 0.6% in the previous 2 years to
6.6% (p < 0.001). The trends for level 1 RTE are indicated in figure 10.
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
21
Figure 10. Trends for most frequently level 1 RTE by process subcode (January 2010 to December 2019)
There has been an increase in level 1 RTE reported associated with ‘on-set imaging:
approval process’ which has increased from 2.7% in the first two-year reporting period
to 12.6% within this reporting period (slope = 2.8%, p = 0.0006). The frequency of ‘on-
set imaging: production process’ associated level 1 RTE has fluctuated over the years
with no clear trend (p = 0.169). ‘Verification of diagnosis/ extent/ stage’ has increased
from 5.4% in the first two-year period to 9.6% (p = 0.0046).
Of note ‘movements from reference marks’, ‘ID of reference marks’ and ‘patient
positioning’ comprised of 33% (n = 25) of level 1 RTE reported in the 2-year period
ending in 2012. These made up 9% (n = 15) of level 1 RTE reports in the most recent
reporting period. It is likely the extended availability and use of image guided RT
(IGRT) has been central to the reduction in these types of errors in recent years.
4.3.2 Breakdown of level 2 (non-reportable radiation incident) RTE
A ‘non-reportable radiation incident’ is defined as a radiation incident which is not
reportable, but of potential or actual clinical significance(7). There were 61 different
subcodes associated with level 2 reports. The most frequently reported level 2 RTE can
be seen in figure 11. These were reported by 43 of the 59 providers that submitted data
for analysis.
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
22
Figure 11. Breakdown of most frequently reported level 2 RTE by process subcode (January 2018 to December 2019, n = 93/ 164 subset of RTE)
The most frequently reported level 2 reports were associated with ‘on-set imaging:
approval process’ (18.9%, n = 31). An example of RTE associated with ‘on-set imaging:
approval process’ includes the mismatch of reference and verification imaging which
does not lead to a total or partial geographical miss as defined as a significant or
unintended accidental exposure.
All the most frequently reported level 2 subcodes have increased since the previous two-year
reporting period, except ‘localisation of intended volume’, which has decreased from 7.7% to
6.1% (p = 0.543). The trends for level 2 RTE are indicated in figure 12.
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
23
Figure 12. Trends for most frequently reported level 2 RTE by process subcode (January 2010 to December 2019)
There has been an increase from 10% within the first two-year reporting period to
18.9% within this reporting period with ‘on-set imaging: approval process’ (slope =
2.3%, p = 0.036) level 2 RTE. There has been an increase in all of the most frequently
reported level 2 subcodes, apart from ‘patient positioning’ which has seen a fluctuation
and slight decrease (slope = −0.1%, p = 0.811).
Of note ‘movements from reference marks’ was the most frequently reported level 2
RTE in the 2-year period ending in December 2012 (12.5%, n = 12). This has been
reduced to 1.9% (n = 3) in the most recent reporting period. It is likely the extended
availability and use of IGRT has been central to the reduction in these types of errors in
recent years.
4.3.3 Breakdown of level 3 (minor radiation incident) RTE
A minor radiation incident is defined as a radiation incident in the technical sense, but
of no potential or actual clinical significance(7). There were 143 different subcodes
associated with level 3 reports. The most frequently reported RTE in this sub-group can
be seen in figure 13. These were reported by all 59 of the providers that submitted data
for analysis.
‘On-set imaging: production process’ made up 31.9% (n = 2,145) of all level 3 RTE.
Further examples of these types of level 3 RTE can be seen in section 4.5.3.
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
24
Figure 13. Breakdown of most frequently reported level 3 RTE by process subcode (January 2018 to December 2019, n = 4,766/ 6,724 subset of RTE)
There hasn’t been a statistically significant change in the most frequently reported level
3 RTE for this reporting period. A decrease in ‘on-set imaging: production process’ from
32.3% to 31.9% (p = 0.643) was seen. The only statistically significant decrease can be
seen with ‘on-set imaging: approval process’ which has decreased from the previous
two-year period, from 7.8% to 5.8% for this two-year period (p < 0.001) (Figure 14).
Figure 14. Trends for most frequently reported level 3 RTE by process subcode (January 2010 to December 2019)
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
25
The main increase seen in the level 3 most frequently reported RTE can be seen with
the increase in ‘on-set imaging: production process’, which has increased from 4.7% in
January 2010 to December 2011 to 31.9% for this reporting period (p < 0.001). This
increase will be linked to the significant update of IGRT since 2010. There has been a
slight decrease in RTE reported associated with ‘use of on-set imaging’ (slope =
−0.5%, p = 0.0009), ‘on-set imaging: approval process’ (slope = −0.7%, p < 0.001) and
‘movements from reference marks’ (slope = −0.7%, p < 0.001).
Of note ‘movements from reference marks’ was the most frequently reported level 3
RTE (7.2%, n = 119) reported in the 2-year period ending in 2012. There has been little
or no change in the frequency of level 3 ‘on-set imaging: recording process’ (slope
=0.07%, p = 0.5754).
4.3.4 Breakdown of level 4 (near miss) RTE
A ‘near miss’ is defined as a potential radiation incident that was detected and
prevented before treatment delivery(7). There were 172 different subcodes associated
with the level 4 RTE. The most frequently reported RTE can be seen in figure 15.
These were reported by 58 of the 59 providers that submitted data for analysis.
The most frequently reported subcode was ‘documentation of instruction/ information’,
making up 7.4% (n = 339) of all level 4 RTE. An example of RTE associated within
‘documentation of instructions’ includes the incorrect entry of information regarding the
set-up, positioning and immobilisation of a patient at pretreatment. These types of RTE
were recognised and rectified at time of patient set up at treatment.
Figure 15. Breakdown of most frequently reported level 4 RTE by process subcode (January 2018 to December 2019, n = 2,123/ 4,577 subset of RTE)
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
26
Figure 16 shows a decrease in percentage of RTE reported associated with ‘accuracy
of data entry’ from 10.0% to 6.4% (p < 0.001) from the previous two-year period to this
reporting period. This is likely due to a general decrease in manual data entry.
However, in the same time there has been an increase in the reporting of level 4 RTE
associated with on-set imaging. The ‘use of on-set imaging’ has increased from 4.1%
during the last two-year period to 6.3% (p < 0.001) and ‘on-set imaging: recording
process’ has increased from 4.8% to 6.2% (p = 0.004).
Figure 16. Trends for most frequently reported level 4 RTE by process subcode (January 2010 to December 2019)
The frequency of level 4 RTE associated with ‘accuracy of data entry’ has decreased
since reporting period January 2010 to December 2011 from 9.3% to 6.4%, (slope =
−0.6%, p = 0.0016). All other level 4 RTE in figure 16 show an increase in frequency of
reporting.
4.3.5 Breakdown of level 5 (other non-conformances) RTE
Other non-conformance is defined as a non-compliance with some other aspect of a
documented procedure, but not directly affecting RT delivery(7).
There were 192 different subcodes associated with the level 5 RTE reported. The most
frequently reported RTE are represented in figure 17. These were reported by 56 of the
59 providers that submitted data for analysis.
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
27
The most frequently occurring subcode was ‘bookings made according to protocol’
making up 5.1% (n = 363) of all level 5 RTE. An example of other non-conformances
associated with ‘bookings made according to protocol’ includes; the incorrect booking
of appointments or not including electronic check lists and on treatment review
appointments. All non-conformances are detected before affecting the patient’s
planning and treatment processes.
Figure 17. Breakdown of most frequently reported level 5 RTE by process subcode (January 2018 to December 2019, n = 2,657/ 7,102 subset of RTE)
The level 5 RTE were then reviewed for this two-year period and compared with
previous two-year reporting periods as shown in figure 18.
Figure 18. Trends for most frequently reported level 5 RTE by process subcode (January 2010 to December 2019)
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
28
Four of the 5 most frequently reported level 5 RTE have increased in percentage since
the last two-year reporting period. The most statistically significant increase was seen
in RTE associated with ‘consent process and documentation’, from 2.4% to 3.4% (p =
0.001). There has been an increase in percentage for all the top 5 reported RTE in this
sub-group over the past 10-year period. The positive slope of each of the trends is
statistically significant (p < 0.001) apart from ‘consent process and documentation’ level
5 RTE which has increased from 1.0% to 3.4% (p = 0.0435), the variability of the data
and the peak in 2012/2013 may be why there is no statically significance for this level 5
pathway code.
Of note ‘management of process flow within planning’ (11.3%, n= 249) was the most
frequently reported of all level 5 RTE in the 2-year period ending in December 2012.
This has been reduced to 2.9% in the most recent reporting period. It is likely the
extended use of electronic booking and task tracking components of oncology
management systems is linked to the reduction in these types of errors in recent years.
4.4 Safety barriers
A safety barrier (SB) is a critical control point, detection method or defence in depth, or
any process step whose primary function is to prevent errors occurring or propagating
through the RT workflow(19). The ‘radiotherapy pathway coding’ has 206 different
process subcodes, including 86 SB(8).
4.4.1 Failed safety barriers
Multiple SB can be allocated to each RTE report to identify all points in the pathway
where the error was not detected (failed SB). Each of the 18,734 RTE reports were
analysed and a total of 13,287 failed SB (FSB) were identified.
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
29
Figure 19. Breakdown of most frequently reported failed safety barrier across all pathway codes by level (January 2018 to December 2019, n = 9,011/ 13,287 subset of RTE)
Figure 19 indicates the most frequently reported FSB, across all pathway codes, was
‘use of on-set imaging’ (10.5%, n = 1,392). ‘End of process checks’ comprised of 34.4%
(n = 4,566) of failed SB reports. ‘End of process checks’ occur at the end of each
discrete part of the pathway and comprise of 6 different pathway codes. These include;
‘mould room/ workshop activities (9k)’, ‘pretreatment activities (10l)’, ‘pretreatment
planning process (11t)’, ‘treatment data entry process (12g)’, ‘treatment unit process
(13hh)’ and ‘brachytherapy (15s)’.
‘End of process checks’ are the last opportunity to identify an error and stop it
propagating across the pathway. Ideally RTE should be identified earlier to mitigate risk
of harm. A further review of the data was undertaken to identify which was the most
frequently reported primary FSB. A total of 6,189 subcodes were identified as a primary
FSB. FSB associated with ‘treatment unit processes’ were attributed to 40.7% (n =
2,516) of all primary FSB. The most frequently reported primary FSB are represented in
figure 20.
Treatment process ‘use of on-set imaging’ was the most frequently reported primary FSB
(13.3%, n = 824) and 8.0% (n = 498) were coded as ‘end of process checks’. Only 2.6% (n =
163) of primary FSB led to a level 1 or 2 RTE, these included ‘on-set imaging: approval
process’ (n = 21/163), which has been discussed in the level 1 RTE (see section 4.3.1) and
‘verification of diagnosis/extent/stage’ (n = 16).
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
30
Figure 20. Breakdown of most frequently reported primary failed safety barrier by level (January 2018 to December 2019, n = 3,742/ 6,189 subset of RTE)
Figure 21 shows the most frequently reported primary FSB from January 2010 to
December 2019. The most statistically significant changes were associated with ‘on-set
imaging: approval process’, which has decreased from 17.5% to 10.3% (p < 0.001),
and ‘management of variations/ unexpected events/ errors’, which has increased from
5.0% to 6.9% (p < 0.001). FSB associated with ‘management of variations/ unexpected
events/ errors’ for example, include the transfer of patients between unmatched linacs
without an appropriate replan. The FSB ‘consent process and documentation’ has also
increased from 3.7% within the previous two-year reporting period to 4.9% within this
reporting period (p = 0.002).
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
31
Figure 21. Trends for most frequently reported primary failed safety barrier (January 2010 to December 2019)
The difference between the most frequently reported primary FSB and FSB across all
reported pathway codes indicates that multiple pathway codes should be shared as an
opportunity for valuable RTE learning.
4.4.2 Effective safety barriers or method of detection
Barriers or control measures are in place across the RT pathway to prevent incidents;
when these barriers fail, incidents can occur. An effective SB (ESB) or method of
detection (MD) can be utilised to identify when the RTE is detected or prevented from
escalating. The first MD code was received in April 2018, between this date and
December 2019, 3,809 reports contained MD. The most frequently reported MD can be
seen in figure 22.
For this reporting period, the most frequently reported MD was ‘on-set imaging:
approval process’ (22.9%, n = 872). This was followed by ‘end of process checks’ as
part of treatment processes (18.9%, n = 711).
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
32
Figure 22. Breakdown of most frequently reported effective safety barrier (method of detection) by level (April 2018 to December 2019, n = 2,732/ 3,809 subset of RTE)
4.5 Causative factors
The use of a causative factor taxonomy enables identification of system problems that
could precipitate a range of different incidents(20). The root cause is an event which
leads to anticipated operational occurrences or accidental conditions(21). A contributory
factor is defined as the latent weakness that allows or causes the observed cause of an
initiating event to happen, including the reasons for the latent weakness. Within the
DoL(8) taxonomy the primary causative factor is the root cause (RC); any subsequent
reported causative factors are considered to be contributory factors (CF). The first
causative factor code was reported in January 2017; therefore, only 3 years of data are
included in this analysis.
4.5.1 Root cause
Figure 23 shows the most frequently reported root cause (RC). A total of 18,405 of the
18,734 (98.2%) RTE reported contained a RC or enough information for PHE staff to
code it. From the RTE which contained a RC the most frequently reported was
individual ‘slips and lapses’, making up 43.8% (n = 8,058) of all RC.
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
33
Figure 23. Breakdown of most frequently reported primary causative factor (root cause (RC)) by level (January 2018 to December 2019, n = 17,848/ 18,405 subset of RTE)
A comparison of 3 years of data can be seen in figure 24.
Figure 24. Percentage of most frequently reported primary causative factor (root cause (RC)) (January 2017 to December 2019, n = 18,983/ 21,699 subset of RTE)
There has been a gradual increase in the RC ‘slips and lapses and ‘equipment and IT
failure’ and ‘communication’ and a gradual decrease in the RC ‘adherence to
procedures/ protocols’ and failure to recognise a hazard. This decrease might be linked
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
34
to the adoption of ‘pause and check’ procedures as recommended by the Society and
College of Radiographers(22).
4.5.2 Level 1 RTE by process subcode and RC
The most frequently reported level 1 process subcodes were broken down by RC
(figure 25), where this information was available.
Figure 25. Correlation between most frequently reported level 1 RTE by process subcodes and primary causative factor (root cause) (January 2018 to December 2019,
subset of RTE)
Level 1 ‘on-set imaging: approval process’ RTE were most frequently reported as RC
‘slips and lapses’ (42.9%, n = 9). Only 9 of the 21 level 1 RTE associated with ‘on-set
imaging: approval process’ included an MD, 5 of which were detected during the offline
review process. ‘Verification of diagnosis/ extent/ stage’ was most frequently reported
as RC ‘decision making process’ (31.3%, n = 5). ‘On-set imaging: production process’
and ‘patient positioning’ were both associated with several different RC and ‘choice of
other concurrent treatment’ was most frequently reported as having a RC of
‘communication’ (66.7%, n = 6).
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
35
4.5.3 Level 3 process subcode ‘on-set imaging: production process’ by RC
A review of the ‘on-set imaging: production process’ subcode of level 3 RTE can be
seen in figure 26. This revealed that 46.2% (n = 987/2,136) related to RC technical,
equipment or IT network failure. Examples of these types of reports included ‘failure of
the image device during image acquisition’, ‘image not captured after exposure’,
flooded image’, or ‘image unavailable offline’. Individual slips and lapses, was related to
39.6% (n = 846/2,136). Examples of which included ‘incorrect imaging parameters
selected’, ‘wrong image acquisition image mode selected’, ‘incorrect blade moved for
image capture’, and ‘imager not extended or appropriately positioned’. This resulted in
additional imaging exposures being undertaken.
RT providers are encouraged to audit and report these events locally so appropriate
and timely preventative measures might be implemented. In addition, the Medicines
and Healthcare products Regulatory Agency (MHRA)(23) should be advised of all
equipment failures.
Figure 26. Breakdown of level 3, ‘on-set imaging: production process’ process subcode RTE by primary causative factor (root cause) (January 2018 to December 2019, n = 2,136)
4.5.4 Contributory factors
Several contributory factor (CF) codes can be attributed to each individual RTE. A
review of the second to fifth causative factor codes indicate the CF associated with an
incident. CF were indicated across 5,028 reports; 810 of these contained multiple CF
totalling 6,106 codes. Figure 27 shows the most frequently reported CF codes. The
most frequently reported CF code was ‘adherence to procedures/protocols’ (41.5%, n =
2,534).
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
36
Figure 27. Breakdown of most frequently reported contributory factors (January 2018 to December 2019, n = 5,670/ 6,106 subset of RTE)
A comparison of 3 years’ data, since the introduction of the CF taxonomy, can be seen
in figure 28. There has been an increase of CF ‘adherence to procedures/ protocols’
from 35.1% to 45.8%. This is of note when considering the importance of adherence to
local procedures and protocols in demonstrating due diligence in clinical care. This
code most frequently followed a RC of ‘slips and lapses’.
Figure 28. Percentage of contributory factors most frequently reported (January 2017 to December 2019, n = 5,405/ 6,865 subset of RTE)
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
37
4.6 Brachytherapy RTE
Brachytherapy (BRT) is a RT sub-speciality which involves the placement of a sealed
source inside or close to the treatment area(24). Reports coded with BRT process codes
as the primary code account for 0.8% (n = 159) of RTE for this two-year reporting
period. BRT makes up less than 3% of all RT episodes(25). The number of BRT
associated RTE would be expected to be low.
The overall number of BRT reports has increased from 85 in the previous reporting period,
reflecting a maturing reporting culture in this area. This represents an 87.1% increase
in RTE reported. Reporting of BRT RTE is to be encouraged to facility learning as the
nature of these events are likely to be different to external beam due to the differences
in their planning and delivery approaches and techniques and technologies employed.
4.6.1 Classification level of BRT RTE
The classification level for BRT RTE was compared to all RTE (including BRT). This
indicated differences in the distribution between datasets (Figure 29). The percentage
of BRT ‘reportable radiation incidents’ (level 1) for this reporting period was 3.1%
compared with 0.9% for all RTE reports (p = 0.004). This might be explained in part by
the hypo-fractionated nature of BRT delivery. There is also a statistically significant
difference between ‘minor radiation incidents’ (level 3) with BRT RTE reported at 15.1%
compared to 35.9% for all RTE reports (p < 0.001). The percentage of other ‘non-
conformances’ (level 5) is also statistically significantly higher within the BRT RTE
reports at 50.3% compared to 37.9% (p < 0.001) for all RTE reports. Figure 29. Breakdown of brachytherapy RTE compared with all RTE by level (January 2018 to December 2019)
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
38
4.6.2 Breakdown of BRT process subcodes
Figure 30 shows the most frequently reported process subcode associated with BRT
RTE was ‘initial positioning of applicators/ sources’ (14.5%, n = 23). An example of this
type of RTE included the application of seeds in the incorrect position. ‘Delivery of
sources’ comprised 11.3% (n = 18) of all BRT RTE. Some 94.4% (n = 17) of these
reports were submitted by a single provider who reported issues with ordering and
delivery of radiopharmaceuticals.
Figure 30. Breakdown of most frequently reported BRT RTE by process subcode
(process code 15) and level (January 2018 to December 2019, n = 109/159)
The percentages of BRT RTE most frequently reported were compared with the
previous two-year period and aggregate data, as shown in figure 31. The most
statistically significant difference in percentage of RTE was ‘delivery of sources’, which
was 1.2% within the last two-year reporting period and 11.3% within this two-year
period (p = 0.005).
The decrease in BRT RTE associated with ‘planning of treatment’ (decrease of 11.8%)
and ‘initial positioning of applicators /sources’ (decrease of 7.9%) are of note. These
are most likely due to the wider adoption of CT based dosimetry and verification
imaging of brachytherapy patients.
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
39
Figure 31. Most frequently reported BRT RTE by process subcode (January 2010 to December 2019, n = 348/593 subset of RTE)
4.6.3 Breakdown of BRT RTE by safety barrier
SB are defined in section 4.4. All SB were broken down by classification as seen in
figure 32.
Figure 32. Breakdown of reported BRT failed safety barrier by level (January 2018 to December 2019, n = 110/113 subset of data)
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
40
The most frequently reported BRT FSB was ‘management of variations’ (23.9%, n =
27) compared with 5.0% (n = 669) for the entire dataset. Only 15.1% (n = 24) of the
BRT RTE reports included an effective SB or method of detection (MD). Of these, the
most frequently reported MD, at 37.5% (n = 9), was ‘end of process checks’.
4.6.4 Breakdown of BRT RTE by causative factor
Causative factors are defined in section 4.5. The most frequently reported root cause
(RC) associated with BRT RTE was ‘equipment or IT network failure’, making up 27.0%
(n = 41) (figure 33). This is different to findings from external beam associated RTE.
This might be due to linear accelerator-based deliveries having better integrated
systems compared with BRT planning and delivery systems.
These 41 ‘equipment or IT network failure’ RC were associated with 12 different BRT
process subcodes. In total 19.5% (n = 8) of these were associated with ‘initial
positioning of applicators/ sources’. ‘Slips and lapses’ made up 23.7% (n = 36) of all
BRT RTE. This is different to the total RTE dataset for this reporting period, where the
most frequently reported RC was ‘slips and lapses’ (43.8%, n = 8,058). ‘Equipment or
IT network failure’ RC made up 10.5% (n = 1,929) of all RTE reported.
Figure 33. Breakdown of most frequently reported brachytherapy RTE by primary causative factors (root cause) and level (January 2018 to December 2019, n = 134/ 152 subset of RTE)
There were 32 contributory factors (CF) across the 159 brachytherapy RTE; the most
frequently reported was ‘adherence to protocols /procedures’, making up 21.9% (n = 7)
of all CF for reported BRT RTE.
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
41
4.7 Inspectorate data
There is a requirement on RT providers to notify the relevant enforcing authority of all
‘reportable radiation incidents’ (level 1) (7, 17, 18). For the purposes of this report the
relevant enforcing authorities will be referred to as the inspectorates hereafter. The
inspectorates for IR(ME)R for England, Northern Ireland, Scotland and Wales were
approached and asked to share anonymised synopses of closed reportable radiation
incidents from January 2018 to December 2019 for analysis.
A total of 300 reports were shared. This is similar to the number of reports shared
between December 2015 to November 2017 (n = 288). On review of the inspectorate
data it became clear that there was some variation in the locally applied classification of
incidents. Some 15.7% (n = 47) of the reported incidents might be coded as level 2 or
3. Examples of these include single repeat CT planning images. As the local provider
deemed the incidents reportable they have either been classified as level 1 or 2 within
figure 34. These level 2 or 3 notifications were excluded from further analysis (n = 253).
The inspectorates published guidance in June 2019(26) which sought to address this
disparity and includes guideline factors for concomitant imaging. The most frequently
occurring subcode within the inspectorate data was ‘on-set imaging: approval process’
(13.7%, n = 41).
Figure 34. Breakdown of most frequent inspectorate notifications by process subcode (January 2018 to December 2019, n = 179/ 300 subset of RTE)
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
42
4.7.1 Breakdown of inspectorate data by process subcodes
The level 1 inspectorate data (n = 253) was then compared to the level 1 voluntary data
(n = 167, figure 35).
‘On-set imaging: approval process’ was the most frequently reported level 1 process
subcode in both datasets. ‘Use of on-set imaging’ made up 1.8% of level 1 voluntary
data, and 5.1% of level 1 inspectorate data. Examples of RTE associated with ‘use of
on-set imaging’ included completion of a daily CBCT in place of kV imaging as part of
verification. ‘Verification of diagnosis/ extent/ stage’ was the second most frequently
reported RTE at 9.6% to the inspectorates.
Figure 35. Comparison of most frequently reported process subcode in inspectorate and level 1 voluntary datasets (January 2018 to December 2019, n = 228/420 subset of data)
The variance in reporting numbers was noted between reporting systems. A total of 59
of 60 UK NHS RT providers submitted data to the voluntary scheme for analysis. This
meant 1 RT provider did not submit data to the voluntary scheme. In addition,
independent RT providers report to the inspectorates but not to the voluntary scheme.
This in part accounts for the disparity in numbers. A further review of the inspectorate
data indicated a notable lag between the incident occurring and the date the report
received at PHE for analysis. This varied between 89 and 1,239 days with an average
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
43
of 515 days. This time lag reflects, only anonymised closed events are shared for
inclusion in this analysis.
To better understand the likely impact of time lag on the variance in number of reports,
a review of the incidents by date of occurrence (between January 2018 and December
2019) was carried out (Figure 36). The trends in the RTE type were similar to those
seen in figure 35.
Figure 36. Comparison of most frequently reported process subcode in inspectorate and level 1 voluntary datasets (Incident date January 2018 to December 2019, n =
195/369 subset of data)
4.7.2 Breakdown of inspectorate data by safety barrier
Safety barriers (SB) are defined in section 4.4. The most frequently reported FSB within
the inspectorate data was reviewed and compared with the level 1 voluntary data
(figure 37). A total of 431 and 190 FSB codes were revealed for the inspectorate and
voluntary data respectively. Treatment ‘end of process checks’ (23.9%, n = 105) was
the most frequently reported FSB followed by ‘on-set imaging: approval process’
(12.1%, n = 52). The order of these was reversed in the voluntary dataset. However,
the number of reports included in the voluntary reported dataset was much smaller.
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
44
Figure 37 Comparison of most frequently reported failed safety barrier in inspectorate and level 1 voluntary datasets (January 2018 to December 2019, n = 353/621 subset of data)
Treatment ‘end of process checks’ is the last opportunity to identify an error before it
affects the patient. RTE need to be identified earlier to mitigate risk of harm. A further
review of the data was undertaken to identify the most frequently reported primary FSB
(figure 38). A total of 130 subcodes were identified. The most frequently reported failed
SB across both datasets was ‘on-set imaging: approval process’ (31.5%, n = 41),
followed by ‘verification of diagnosis/ extent/ stage’ (14.6%, n= 19).
Figure 38. Comparison of most frequently reported primary failed safety barrier in inspectorate & level 1 voluntary datasets (January 2018 to December 2019, n = 146/216 subset of data)
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
45
There was sufficient detail in the inspectorate data to assign effective safety barriers
(method of detection (MD)) to the inspectorate data (Figure 39). The first MD code in
the voluntary dataset was received part way through the reporting period (April 2018).
A total of 48 level 1 reports included MD. The most frequently reported MD was ‘on-set
imaging: approval process’ (30.4%, n = 77 and 33.3%, n = 16 respectively). This was
followed by ‘end of process checks’ as part of treatment processes (28.1%, n=71 and
18.8%, n = 9)
Figure 39. Comparison of most frequently reported effective safety barrier in inspectorate & level 1 voluntary datasets (January 2018 to December 2019,
n = 231/301subset of data)
4.7.3 Breakdown of inspectorate data by causative factor
Causative factors, root cause (RC) and contributory factors (CF) are defined in section
4.5. The RC were reviewed for the level 1 inspectorate and voluntary data as seen in
figure 40.
The majority of the level 1 inspectorate data (n = 253) and voluntary reports (n = 162)
included RC codes or sufficient free text to allocate a code to them. The most
frequently reported RC within the inspectorate data was ‘slips and lapses’ (39.5%, n =
100). This was followed by ‘communication’ (18.2%, n = 46). Examples of this type of
report included a failure in communication between outside departments or wards and
the RT department, or failings associated with sharing of referral data.
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
46
Figure 40. Comparison of most frequently reported root cause in inspectorate & level 1 voluntary datasets (January 2018 to December 2019, n = 351/415 subset of data)
The CF were reviewed for the inspectorate data and compared with the level 1
voluntary data (figure 41).
Figure 41. Comparison of most frequently reported contributory factor in inspectorate and level 1 voluntary datasets (January 2018 to December 2019, n = 200/294 subset of data)
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
47
Not all of the inspectorate data or voluntary RTE reports included RC codes or
sufficient free text to allocate a code to them. In total 97.7% (n = 208) of the level 1
inspectorate data and 55.1% (n = 86) of the voluntary level 1 RTE contained a RC. The
most frequently reported CF in the inspectorate data was ‘adherence to procedures/
protocols’ (23.1%, n = 48). The CF ‘slips and lapses’ made up 18.8% of both datasets
(inspectorate data n = 39, voluntary data n = 16).
5. Discussion
Participation in the national voluntary reporting and learning scheme(9, 10, 27) is indicative
of an open and transparent safety culture. This provides opportunities to learn from a
greater pool of data and facilitates local benchmarking of events with the national
picture to support a reduction in the magnitude and probability of RTE. Learning from
RTE should be local, national and international.
Outputs from RTE analysis should be used to inform prospective risk assessments in
thematic areas identified in the analysis as part of a study of the risk of accidental and
unintended exposures.
The European Commission(3) advocates proactive risk assessment as an effective tool
of risk management in RT to identify preventative measures. The EC provides a useful
definition for risk management as referring to “all the various organizational structures
and processes that are designed to improve safety and prevent or reduce risks, or that
limit the consequences of risks (that is, all risk preventive measures). Risk
management is, therefore, part of the overall quality management program.”
A study of risk, or a proactive risk assessment is a process that helps organisations to
understand the range of risks (both internal and external) that they face, their capacity
to control those risks, the likelihood (probability) of the risk occurring and the potential
impact thereof. This involves quantifying risks, using judgment, assessing and
balancing risks and benefits and weighing these against cost(3).
5.1 Increase in RTE reporting
Between January 2010 and December 2019, 100% of NHS providers across the UK
voluntarily reported 58,913 RTE to the national reporting and learning system. Of
these, 32.0% (n = 18,853) were reported between January 2018 and December 2019.
As seen in figure 1 the average number of reports submitted monthly to the national
voluntary scheme increased by 15.6% from 680 in the previous two-year reporting
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
48
period to 786 within this two-year period. A significant increase in reporting over time
has been seen in other incident learning systems(28).
Although 100% of NHS RT providers have reported to the national analysis only 98.3%
(n = 59) reported between January 2018 and December 2019. This decrease in
reporting may be due to local resourcing challenges and change to local reporting
procedures. There is also some disparity in the number of reports received per provider
per month. Reporting levels ranged from 1 to 1,450 reports per provider over the two-
year period. There may be a number of reasons for this disparity. These includes the
differences in local reporting systems used such as whether they are electronic or
paper based, or if there is a requirement to use more than one reporting system. Also,
reporting culture may vary within providers. Moreover, providers differ in terms of the
RT services they provide and capacity, and the number of reports per provider has not
been normalised to account for this variation. This variation is also reflected in the lag
time for reporting, which ranged from 0 days to 658 days. The PSRT encourage all RT
providers to report monthly. Providers can contact PHE ([email protected])
with reporting queries or if they would like further advice on participation in this scheme.
The increase in RTE reported monthly should be interpreted with care and
demonstrates the commitment RT providers have to improving patient safety in RT and
reflects a mature reporting culture. It is expected that a further increase in reporting
continues as providers further develop full electronic reporting solutions allowing all
levels of RTE to be reported nationally.
NHS England included the requirement to engage in national reporting and learning
from RTE and the use of the TSRT(7) and DoL(8) taxonomies as part of the external
beam service specification(29). Regulation 8(3) of the IR(ME)R regulations requires the
recording of analyses of events involving or potentially involving accidental or
unintended exposures (7, 17, 18). Additionally, recommendations of the Francis report(30)
into failings at the Mid-Staffordshire NHS Foundation Trust included a requirement for
openness, transparency and candour throughout the NHS to support a culture of
protecting patients and removing poor practice. The patient safety ethos and
recommendations within these documents have mainly been adopted across the UK
with 98.3% of all NHS providers reporting over this two-year period, indicating a mature
reporting culture.
According to the Radiotherapy Dataset(25), the estimated number of prescriptions
across NHS providers within England for this reporting period was 346,488 across
3,701,280 attendances. This data was extrapolated for the UK population to an
estimated 415,786 prescriptions across 4,441,536 attendances. To establish a reported
error rate, it was accepted the clear majority of RTE reported affected a single
attendance as part of a prescription. With this caveat an estimated reported RTE rates
of 4 per 1,000 attendances or 45 per 1,000 prescriptions were calculated. It is worth
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
49
noting that the clear majority of these events did not impact on the patients’ planning or
treatment. However, using the same premise an estimated report RTE rate for level 1
events was calculated as 0.4 per 1,000 prescriptions.
5.2 Main themes
5.2.1 Breakdown of process codes
The reported RTE were spread across all 21 categories of process code (as seen in
section 4.1.1); treatment unit process codes were the most frequently reported RTE
(42.3%, n = 7,923). The treatment process represents the last opportunity to identify
errors. Accurate treatment relies on the correct interpretation of the treatment plan and
set-up details which need to be replicated at each fraction of treatment. This might
explain prevalence of RTE reported associated with ‘treatment unit processes’.
When reviewing the data for this two-year period (January 2018 to December 2019)
against the previous two-year period (January 2016 to December 2017) there has been
a significant decrease in RTE reported in the treatment data entry process. This
decrease may be due to a gradual change in data entry processes from manual
transcription to electronic transfer of data, reducing the requirement for manual data
transfer process. This had already been largely achieved for radical treatments and
more recently for palliative treatments.
5.2.2 Breakdown of process subcodes
‘On-set imaging: production process’ made up 12.3% (n = 2,310) of all the RTE
reported for this two-year reporting period. Most of these RTE were classified as level 3
(92.9%, n = 2,145). These RTE were seen to be largely on-treatment verification
images.
Imaging associated RTE have increased within this two-year reporting period. These
RTE included: ‘on-set imaging: production process’, ‘use of on-set imaging’ and ‘on-set
imaging: recording’. The incidence of on-set imaging associated RTE reflects the
increase in automation in set-up and the focusing of decision making processes during
on-set imaging resulting in more imaging related errors. This is reflected in the level of
data and image interpretation required as part of imaging processes. This risk may be
amplified due to the dynamic nature of online review and the rapid pace of
development of new technologies. This equates to more imaging-based errors.
However, the benefit IGRT brings to the patient is clear. Further guidance on imaging
associated RTE has been published(31).
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
50
Although there has been a general increase in RTE associated with ‘use of on-set
imaging’ there was a peak within the reporting period January 2014 to December 2015
and a gradual decrease thereafter. The decrease from this peak may be due to the
uptake of more competency-based imaging review protocols and adoption of national
guidance on the implementation and use of IGRT(32). Consideration should be given to
introducing a ‘pause and check’ policy for on-line image capture, review and approval
to reduce these types of RTE.
In areas demonstrating an initial increase in RTE that are then seen to fall, such as on-
set imaging, Learning from Excellence (LfE) may be useful. By reporting and studying
successes from RT providers, learning can be augmented, patient outcomes improved,
with LfE also impacting positively on resilience and culture in the workplace(33).
5.3 Classification level of RTE
The majority of reports were classified as lower level events, thus not affecting the
treatment outcome for the patient. Of the level 1 and 2 RTE reported, it is known most
of them affected only one fraction of a course of treatment. This meant that corrective
action could be taken over the remaining treatment fractions. There has been an
increase in the reported level 3 incidents; this may be due to the increase in imaging-
associated RTE as discussed in section 5.2.2.
Figure 42. Comparison of Heinrich’s triangle with RTE data (January 2018 to December 2019, January 2016 to December 2017, January 2010 to December 2019)
A small number of higher level incidents and a much greater number of lower level
incidents are consistent with findings in the literature(34). It is known that for every level
1 incident that occurs, many lower level incidents are also seen. Heinrich illustrated this
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
51
point in 1931(34). It may be seen that as the severity of an incident decreases, the
probability of its occurrence increases.
It can be seen in figure 42 that there are more lower level incidents from this voluntary
reporting system, however the ratios are different to Heinrichs’s illustration. This might
be explained by the fact that all providers do not report all levels of RTE. Where all
levels of RTE are not shared for analysis there are missed opportunities for learning
form these events. A 2018 survey(15) of RT providers, showed providers were less likely
to submit level 5 RTE nationally where dual local reporting and learning systems were
in operation as to do so would require additional resource.
The most frequently reported level 1 RTE process subcode was ‘on-set imaging:
approval process’ (12.5%, n = 21), as seen in section 4.3. Most of these ‘on-set
imaging: approval process’ level 1 RTE, were associated with individual causative
factors (85.7%, n = 18). The incidence of on-set imaging associated RTE reflects the
level of manual input and interpretation involved in imaging processes. These types of
RTE were detected after the treatment occurred and were most frequently detected
during the review process as part of the offline review process. Of note is the increase
in ‘verification of diagnosis/ extent/ stage’ reported RTE from 2.2% in the two-year
period January 2012 to December 2013 to 9.6% in January 2018 to December 2019.
Consideration should be given to ensure robust referral guidelines and procedures are
in place to make sure all required diagnostic information is accessible prior to
justification and authorisation of treatment and made available to inform planning
processes.
There were 52 different subcodes associated with the 167 level 1 RTE. Of the 52
different process subcodes reported only 32 were present in the previous two-year
reporting period. This demonstrates the importance of ongoing cyclic monitoring of
RTE.
There were 61 different process subcodes included in reported level 2 RTE. The most
frequently reported level 2 RTE subcode was ‘on-set imaging: approval process’ (18.9%, n =
31). This subcode was the most frequently reported RTE across both level 1 and 2 reports.
This may be due to the increasing frequency in the use of verification imaging and the post
treatment checks which are in place to detect these types of errors. The main difference
between a level 1 and level 2 RTE associated with ‘on-set imaging: approval process’ is that a
level 1 RTE would equate to a complete or significant geographical miss, whereas a level 2
would not.
There were 143 different process subcodes included in level 3 reports. The most
frequently reported subcode was ‘on-set imaging: production process’, making up
31.9% (n = 2,145). Of these, 46.2% (n = 987) were related to individual ‘slips and
lapses’ and 39.6% (n = 846) related to equipment failure. The errors associated with
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
52
equipment malfunction were spread across manufacturers and were mainly related to
on-set imaging devices. Consideration should be given to undertaking a risk
assessment in the case of frequently recurring fault, especially where no resultant
image acquisition is achievable to inform the treatment process, as to whether imaging
on that device should continue.
The main increase seen in the level 3 most frequently reported RTE can be seen with
the increase in ‘on-set imaging: production process’, which has increased from 4.7% to
31.9% over the past 10 years.
Equipment failure reports should be reported to local engineers, the manufacturer and
the MHRA(23) as appropriate. Accidental or unintended reportable radiation incidents
associated with equipment failure should also be reported to the relevant enforcing
authority(26).
There were 172 process subcodes included in reported level 4 RTE. The most
frequently reported subcode was ‘documentation of instruction/ information’ (7.4%, n =
339). Only 71 of this subset of RTE contained an effective safety barrier (MD). Of
these, 33.8% (n = 24/71) indicated the RTE was detected during patient set up and
28.2% (n = 20/71) were detected during end of process checks at the treatment stage.
This indicates these type of RTE were not picked up at the ‘end of process check’
stage during pretreatment. It has been stated that end of process checks are some of
the most important processes to identify safety issues(35). Consideration should be
given to reviewing the effectiveness and timing of these interventions to ensure they
are optimal in the pathway for the mitigation of RTE.
Since the previous two-year period, there has been a decrease in the RTE associated
with both ‘documentation of instructions/ information’, from 8.0% to 7.4%, and
‘accuracy of data entry’, from 10.0% to 6.4%. The reduction in these 2 level 4 process
subcodes could be due to an uptake in the use of electronic systems leading to a
reduction of manual transcription, particularly for palliative treatments. Consideration
should be given to reviewing and extending the use of electronic systems wherever it
can contribute to the reduction of RTE. The palliative, superficial and brachytherapy
pathways might benefit from this in particular.
Within level 5 RTE reports the process subcode ‘consent process and documentation’
has increased from 2.4% (n = 155) in the previous two-year reporting period to 3.4% (n
= 239) within this reporting period. There was also a peak seen in the two-year
reporting period January 2012 to December 2013 at 5.7% (n = 183). There may be
some correlation between this peak, and subsequent reduction in percentage of this
type of RTE with the uptake of electronic consent processes.
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
53
5.4 Safety barriers
It is known there are risks inherent in the planning and delivery of RT. Therefore, a
number of safety barriers (SB) are built into the patient pathway to identify and stop
RTE propagating across the pathway and affecting the patient. Analysis of SB can
identify failed and effective safety barriers, so resources might be focused where they
would be most beneficial in mitigating RTE.
All failed SB subcodes were analysed across the 18,734 RTE reports for this two-year
period, and a total of 6,189 subcodes were identified as FSB. Primary FSBs associated
with ‘treatment unit processes’ were attributed to 40.7% (n = 2,516) of all failed SB.
This might be explained as ‘treatment unit process’ codes were the most frequently
reported across all RTE (42.3%, n = 7,923). ‘Use of on-set imaging’ process subcode
was the most frequently reported failed SB (13.3%, n = 824).
The most frequently reported MD was ‘on-set imaging: approval process’ (22.9%, n =
872) and 10.0% of all FSB. This MD is designed specifically to pick up errors in patient
position before treatment occurs, and as seen in section 4.4.2, detected several patient
position RTE, including ‘movements from reference marks’, ‘patient positioning’ and
imaging associated RTE. Although the subcode ‘on-set imaging: approval process’ was
the most frequently reported level 1 and 2 subcode (see sections 4.3.1 and 4.3.2) this
was also the most frequently reported MD, making this an effective safety barrier. The
increase in the use of online image verification has already been discussed in this
report.
5.5 Causative factors
Not all RTE contained a causative factor, nor contained enough detail to code. The
PSRT recommends all RTE contain all taxonomies and includes enough text to
appropriately define the event. The benefit of the use of causative factor taxonomy is
that it enables identification of system problems or root causes that could precipitate a
range of different incidents. If the root causes are addressed, it can be expected that
overall system safety is enhanced and not just a weakness associated with a particular
incident(20). For example, if the most frequently occurring equipment malfunction issues
associated with CBCT failures are addressed, the number of level 3 RTE associated
with ‘on-set imaging: production process’, 987 level 3 RTE, could be significantly
reduced.
The most frequently reported RC was individual ‘slips and lapses’ (n = 8,058). This is
consistent with findings in the literature. It has been suggested that human error is a
determining factor in 70 to 80% of incidents occurring in medicine(36). As seen in
section 4.5.1 there has been a gradual decrease in the RC ‘adherence to
procedures/protocols’ and an increase in ‘slips and lapses’ this is due to the uptake in
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
54
using multiple codes and the assigning of both ‘slips and lapses’ as the RC and
‘adherence to procedures/protocols’ as a CF. The increase in the reporting of
‘adherence to procedures/protocols’ as a CF is of note. This is particularly of note when
considering the importance of adherence to local procedures and protocols in
demonstrating due diligence in clinical care. Consideration should be given locally to
this and a review undertaken of the accessibility of quality management systems
(QMS). This might extend to the location of the QMS and access rights to electronic
QMS. Also activate engagement of staff in review of procedures is key to ensuring they
are fit for purpose. The RC ‘communication’ was the second most frequently reported
(15.2%, n = 2,799) code. This is consistent with findings from other reporting and
learning systems(35).
5.6 Brachytherapy RTE
BRT is a sub-specialty of RT, so it is expected the number of BRT RTE would be low
(n=159). It was noted there was a higher percentage of level 1 BRT RTE at 3.1%
compared to the 0.9% for all RTE. This might be explained in part by the hypo-
fractionated nature of BRT delivery. The clear majority of RT is by external beam
delivery which tends to have a longer fractionation scheme that allows for correction. A
difference was also noted in the level 3 RTE; only 15.1% of the BRT RTE were
classified as level 3 compared with 35.9% of all RTE. This difference in level 3 RTE
may be due to the differences in the uptake of IGRT between BRT and external beam
RT.
The most frequently occurring process subcode associated with BRT RTE was ‘initial
positioning of applicators/ sources’ (14.5%, n = 23). The most frequently reported RC
associated with brachytherapy RTE was ‘equipment or IT network failure’ (27.0%, n =
41). This is different to the most frequently reported RC for all RTE, ‘slips and lapses’.
This difference may be due to the variance in BRT and external beam techniques.
For the entire dataset, there is a disparity in the number of reports received per
provider per month. Within the small BRT dataset, a single provider may skew the data.
This can be seen within the BRT process subcode ‘delivery of sources’ (11.3%, n = 18),
the majority (94.4%, n = 17) of which were reported by a single provider.
5.7 Inspectorate data
A total of 300 reports were received from the IR(ME)R inspectorates compared to 167
from the voluntary reporting scheme. This difference may be due to several different
factors. Firstly, only anonymised closed events were shared by inspectorates which
may create a difference in time lag. In reviewing this PHE will look at reducing this lag
by incorporating inspectorate analysis into the triannual analysis(11). Secondly, the
voluntary data does not include data from independent providers. There is also some
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
55
disparity in the locally applied classification of events as seen in section 4.7. Finally, it
is known that barriers to reporting include reporting to multiple reporting systems(37).
For this two-year reporting period, the process subcode ‘on-set imaging: approval
process’ has been the most frequently reported pathway subcode. This extended to
most frequently reported failed SB and MD across both the inspectorate and level 1
voluntary data. The use of IGRT to aid patient set up and verify treatment position has
now become embedded within standard RT practice. Due to the frequency in using
IGRT there has been a sustained increase in on-set imaging associated RTE. Although
there are differences in the number of level 1 RTE reported to the relevant inspectorate
and the voluntary reporting system, the most frequently reported primary subcode,
failed SB, MD and the causative factor were the same across both datasets.
UK RT providers have well-established local reporting and learning systems in place for
the recording, investigation, escalation, analysis and learning from RTE. IR(ME)R (Reg
8(3)) mandates this practice (17-18).
Documentation relating to RTE should be retained in line with relevant guidance(38). RT
providers should have a forum which includes a record of RTE that is available for all
staff to review to ensure best practice is maintained, by sharing lessons learnt with all
staff locally and applying lessons learnt to mitigate RTE.
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
56
6. Conclusion
Staff are more likely to report RTE where there is an open reporting culture and where
the clear aim of reporting is to learn and to improve patient safety. High reporting
numbers of RTE is indicative of an awareness of safety issues among healthcare
professionals and a well-established reporting culture.
Reporting of RTE will only be effective if there is a willingness to learn from errors and
to alter practice accordingly. Employers should share the outcomes of analyses with all
relevant staff and apply lessons learnt to mitigate these events in future.
Although 100% of RT NHS providers across the UK have reported to the RT reporting
and learning system since the introduction of this scheme, analysis indicates one
provider has not submitted data for this 2-year period. Also, it is noted that not all
providers report all levels of RTE, particularly ‘near miss’ and ‘other non-conformances’.
It is expected that numbers of RTE reports will continue to increase with the
consolidation of local reporting services and through the redevelopment of the NRLS as
PSIMS.
An estimated reported RTE rate of 4 per 1,000 attendances or 45 per 1,000
prescriptions was calculated. An estimated reported RTE rate for level 1 events was
calculated as 0.4 per 1,000 prescriptions. It is worth noting that the clear majority of
these events did not impact on the patients’ planning, treatment or outcome.
For the first time this two-year report includes learning from across all taxonomies,
including the classification, pathway coding, safety barriers, methods of detection and
causative factor taxonomy. The use of all taxonomies allows wide-ranging learning from
RTE at local, network and national level.
Consistent with findings in the literature, there are a small number of significant
incidents and a greater number of lower level incidents. The proportion of significant
incidents has continued to decrease slightly since the previous two-year period.
On-set imaging associated RTE made up a significant proportion of all reported RTE.
This reflects the increase in automation of processes across the RT pathway. On-set
imaging processes now represent a focal point for decision making processes on the
pathway and is the last point on the pathway prior to initiating treatment exposures. The
most frequently reported root cause of RTE was individual ‘slips and lapses’. This is
reflected in the level of manual input and data and image interpretation required as part
of imaging processes. The risk of error in imaging processes may be amplified due to
the dynamic nature of online review and the rapid pace of development of new
technologies and techniques, together with an increase in imaging frequency. This
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
57
equates to more imaging-based errors. However, the benefit image guided RT (IGRT)
brings to the patient is clear. Further guidance on imaging-associated RTE has been
published(31).
Outputs from RTE analysis should be used to inform prospective risk assessments in
thematic areas identified in the analysis as part of a study of the risk of accidental and
unintended exposures to further mitigate against these types of RTE.
In areas demonstrating an initial increase in RTE that then are seen to fall, such as on-
set imaging, Learning from Excellence (LfE) may be useful. By reporting and studying
successes from RT providers, learning can be augmented and patient outcomes
improved; this also impacts positively on resilience and culture in the workplace(33).
RT is ever evolving with new techniques and technology; therefore, these trends should
continue to be reported and learnt from. The move to increased hypo-fractionation of
external beam RT will reduce the opportunities to correct for RTE. The role of reporting
and learning systems will continue to play a part in helping identify and address RTE.
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
58
7. Recommendations
Recommendations for local providers are that:
• all UK RT providers should continue to use Towards Safer Radiotherapy(3) and
Development of Learning(4) taxonomies to code all levels of RTE for local analysis
to inform local learning and practice
• UK NHS RT providers should continue to submit fully coded RTE reports, of all
levels, to the national voluntary reporting system using the mechanisms identified
within this report, monthly, to ensure timeliness of shared learning
• adherence to protocols / procedures and slips and lapses are the most frequently
reported causative factors – RT providers should consider working arrangements
associated with these reports
• consideration should be given to introducing a ‘pause and check’ policy for on-line
image capture, review and approval to reduce IGRT associated RTE
• a review of referral guidelines and procedures should be undertaken to ensure all
required diagnostic information is in place prior to justification and authorisation of
treatment and made available to inform planning processes to minimise the risk of a
missed verification of diagnosis / staging of disease
• consideration should be given to reviewing the effectiveness and timing of ‘end of
process checks’ to ensure they are optimal in the pathway to mitigate RTE
• local learning should be compared with the national picture and used to inform local
and network level practice
• independent providers should consider submitting RTE to the national voluntary
reporting system
• RTE analysis should be used to inform prospective risk assessments as part of a
study of the risk of accidental and unintended exposures to support compliance with
IR(ME)R (Regulation 8(2) and 8(3))
National recommendations are that:
• PSRT should continue to develop the national analysis and learning from RTE, with
timely dissemination of findings to the RT community for wider learning
• RTE should be used by the PSRT and individual RT providers as part of a risk-
based approach to allocating resources for improving patient safety in radiotherapy
and to inform audit and research
• PSRT should engage vendors in developments to reduce the rate of RTE related to
equipment failure and human factors.
• in areas demonstrating an initial increase in RTE that are then seen to fall, Learning
from Excellence may be useful. PSRT should develop RT based tools to support the
implementation of emerging patient safety theory
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
59
8. Acknowledgements and PSRT Steering
Group membership
Acknowledgements
The Patient Safety in Radiotherapy Steering Group would like to thank all stakeholders
for their ongoing commitment to advancing safer RT. We hope this report will support
the RT community by informing their practice. In particular, we would like to thank:
• NHS RT Providers and RTE reporters across the UK
• National Reporting and Learning System (NRLS) at NHS England and Improvement
• enforcing authorities for IR(ME)R across the UK
• the Care Quality Commission (CQC) in England
• the Regulation and Quality Improvement Authority (RQIA) in Northern Ireland
• Healthcare Improvement Scotland (HIS) in Scotland
• Healthcare Inspectorate Wales (HIW) in Wales
• the National Cancer Registration and Analysis Service (NCRAS) – this work uses
attendance and prescription data that has been provided by patients and collected
by the NHS as part of their care and support; the data is collated, maintained and
quality assured by NCRAS, which is part of Public Health England
• Wei Zhang (Medical Statistician, Public Health England)
PSRT Steering Group membership
• Julia Abernethy (Patient Safety Team, NHS England and Improvement)
• Helen Best (Public Health England)
• Martin Duxbury (Society and College of Radiographer’s Clinical Representative –
Deputy Head of Radiotherapy, St James Institute of Oncology, Leeds)
• Úna Findlay (Public Health England and Group Chair)
• Petra Jankowska (Royal College of Radiologists – Consultant Clinical Oncologist,
Taunton and Somerset Foundation Trust and Quality and Safety Lead at RCR)
• Maria Murray (Society and College of Radiographers – Professional Officer for
Scotland and UK Radiation Protection Lead)
• Tony Murphy (Lay Representative)
• Carl Rowbottom (Institute of Physics and Engineering in Medicine – Head of
Physics, The Clatterbridge Cancer Centre NHS Foundation Trust)
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
60
9. References
1. Dunscombe P. Personal communication with Úna Findlay. 2012. 2. Hartvigson PE, Kusano AS, Nyflot MJ, Jordan L, Dinh TK, Sponseller PA, et al. Durable
Improvement in Patient Safety Culture Over 5 Years With Use of High-volume Incident Learning System. Practical radiation oncology. 2019;9(4):e407-e16.
3. European Commission. Radiation Protection No. 181, General guidelines on risk management in external beam radiotherapy. https://ec.europa.eu/energy/sites/ener/files/documents/RP181web.pdf, 2015.
4. World Health Organization. Reporting and learning for patient safety. https://www.who.int/patientsafety/implementation/reporting_and_learning/en/
5. NHS Improvement. NRLS organisation patient safety incidents reports: commentary. 2019. https://improvement.nhs.uk/documents/5066/OPSIR_commentary_March_2019_Final.pdf.
6. Department of Health. Radiotherapy: Hidden Dangers. Chapter 5. Chief Medical Officer’s Annual Report 2006 (2007). https://webarchive.nationalarchives.gov.uk/20130105021748/http://www.dh.gov.uk/en/Publicationsandstatistics/Publications/AnnualReports/DH_076817.
7. Royal College of Radiologists, Society and College of Radiographers, Institute of Physics and Engineering in Medicine, National Patient Safety Agency, British Institute of Radiology. Towards Safer Radiotherapy. London: Royal College of Radiologists, 2008. https://www.rcr.ac.uk/system/files/publication/field_publication_files/Towards_saferRT_final.pdf.
8. Public Health England. Radiotherapy: learning from errors. https://www.gov.uk/government/publications/development-of-learning-from-radiotherapy-errors.
9. Public Health England. Radiotherapy error and near misses: biennial report. https://www.gov.uk/government/publications/radiotherapy-errors-and-near-misses-data-report.
10. NHS Improvement. Report a patient safety incident. https://improvement.nhs.uk/resources/report-patient-safety-incident/
11. Public Health England. Safer Radiotherapy: supplementary analysis. https://www.gov.uk/government/publications/safer-radiotherapy-error-data-analysis-report.
12. NHS Improvement. National patient safety incident reports. https://improvement.nhs.uk/resources/national-quarterly-data-patient-safety-incident-reports/
13. NHS Improvement. The future of patient safety incident reporting: upgrading the NRLS. https://improvement.nhs.uk/resources/development-patient-safety-incident-management-system-dpsims-project-completes-its-alpha-phase/
14. National Patient Safety Agency. Implementing Towards Safer Radiotherapy: guidance on reporting radiotherapy errors and near misses effectively. https://webarchive.nationalarchives.gov.uk/20110318152355/http://www.nrls.npsa.nhs.uk/resources/clinical-specialty/radiology-and-radiotherapy/?entryid45=75033&p=1
15. Public Health England. Safer Radiotherapy: Newsletter. https://khub.net/web/phe-national/public-library/-/document_library/v2WsRK3ZlEig/view/280803556?_com_liferay_document_library_web_portlet_DLPortlet_INSTANCE_v2WsRK3ZlEig_redirect=https%3A%2F%2Fkhub.net%3A443%2Fweb%2Fphe-national%2Fpublic-library%2F-%2Fdocument_library%2Fv2WsRK3ZlEig%2Fview%2F280803345
16. NHS Improvement. NRLS organisation patient safety incidents reports: commentary. 2020. https://improvement.nhs.uk/resources/national-patient-safety-incident-reports-25-march-2020/
17. The Ionising Radiation (Medical Exposure) Regulations 2017. The Stationery Office, London, SI 2017/1322. http://www.legislation.gov.uk/uksi/2017/1322/contents/made
18. The Ionising Radiation (Medical Exposure) Regulations (Northern Ireland) 2018. The Stationery Office, London, SR 2018/17. http://www.legislation.gov.uk/nisr/2018/17/contents/made .
19. Ford E et al. Consensus recommendation for incident learning database structures in radiation oncology. Medical Physics, 39 (12), 7272-7290, 2012 December.
Biennial radiotherapy error data analysis and learning report: January 2018 to December 2019
61
20. Clark B et al. The management of radiation treatment error through incident learning. Radiotherapy and Oncology, 2010, Vol 95, pp344-349.
21. Boadu M & Mohan Rehani M. Unintended exposure in radiotherapy: Identification of prominent causes. Radiotherapy and Oncology, 2009, Vol 93, pp609-617.
22 Society and College of Radiographers. Have you paused and checked? Radiotherapy, SCoR 2017. https://www.sor.org/learning/document-library/have-you-paused-and-checked-radiotherapy
23. Medicines and Healthcare products Regulatory Agency. Report a problem with a medicine or medical device https://www.gov.uk/report-problem-medicine-medical-device..
24. Felder S, Morley L, Ng E, Chan K, Ballantyne H, Di Tomasso A, et al. Brachytherapy patient safety events in an academic radiation medicine program. Brachytherapy. 2018;17(1):16-23.
25 Cancer stats https://cancerstats.ndrs.nhs.uk. 26. Care Quality Commission. Significant accidental and unintended exposures under IR(ME)R:
Guidance for employers and duty-holders. https://www.cqc.org.uk/sites/default/files/20190603_significant_accidental_and_unintended_exposures_guidance.pdf.
27. Public Health England. Safer Radiotherapy: supplementary survey analysis. https://www.gov.uk/government/publications/safer-radiotherapy-supplementary-survey-analysis
28. Wright JL, Parekh A, Rhieu BH, Miller D, Opris V, Souranis A, et al. Adoption of an incident learning system in a regionally expanding academic radiation oncology department. Reports of practical oncology and radiotherapy : journal of Greatpoland Cancer Center in Poznan and Polish Society of Radiation Oncology. 2019;24(4):338-43.
29. NHS England. External Beam Radiotherapy Services Delivered as part of a Radiotherapy Network (Adults), 2019. https://www.england.nhs.uk/commissioning/spec-services/npc-crg/group-b/b01/
30. Francis R. Report of the Mid Staffordshire NHS Foundation Trust public enquiry, London: HMSO, 2013. https://www.gov.uk/government/publications/report-of-the-mid-staffordshire-nhs-foundation-trust-public-inquiry
31. Public Health England. Radiotherapy: good practice. https://www.gov.uk/government/publications/radiotherapy-good-practice-in-error-reporting.
32. National Radiotherapy Implementation Group. Image Guided Radiotherapy. Guidance for implementation and use. National Cancer Action Team (2012). https://www.sor.org/sites/default/files/document-versions/National%20Radiotherapy%20Implementation%20Group%20Report%20IGRT%20Final.pdf
33. Kelly N BSPA. Learning from excellence in healthcare: a new approach to incident reporting. Archves of Disease in Childhood. 2016;101(9).
34. HW H. Industrial Accident Prevention: A Scientific Approach. New York: McGraw Hill Book Company; 1931.
35. Sun B, Zhao T, Guta A, Kamal G, Zhang T, Mutic S. Patient Safety and Process Improvements in Radiation Therapy through 10 Years of Incident Reporting and Learning. International Journal of Radiation Oncology Biology Physics. 2019;105(1).
36. Vincent C, Bas de Mol. Safety in Medicine. Oxford: Elsevier, 2000. 37. Moran K, Hollenhorst H. Successes and barriers to the integration of the national systen for incident
reporting radiation treatment (NSIR-RT) taxonomy into a provincial incident reporting and learning system. Radiotherapy and Oncology. 2019;139.
38. NHS Digital. Records Management Code of Practice for Health and Social Care 2016. https://digital.nhs.uk/data-and-information/looking-after-information/data-security-and-information-governance/codes-of-practice-for-handling-information-in-health-and-care/records-management-code-of-practice-for-health-and-social-care-2016.