challenges in credentialing institutions and participants in advanced technology clinical trials...

2QA for Advanced Technology, Dallas, February 2007

Learning Objectives Role of RPC in support of clinical trials

Sources of requirements for credentialing

Goals of credentialing Procedures for credentialing Results from credentialing procedures

Remaining challenges in credentialing

QA for Advanced Technology, Dallas, February 2007


Brief Background Formed by agreement between AAPM and CRTS

Founded in 1968 to monitor institution participation in clinical trials

Funded continuously by NCI as structure of cooperative group programs have changed

Credentialing added as complexity of trials has increased

Now 38 years of experience of monitoring institutions and reporting findings to study groups and community


NCINCI

QARCQARC

RPCQA PROGRAM

RPC QA PROGRAM

ITC(High tech Protocols)

ITC

RTOG/ACRRTOG/ACR

RCETRCET

RPC has relationships with all study groups and with Advanced Technology Consortium

ACOSOGCOGSWOGCALGBECOGNSABPNCCTGGOG

ACRINRTOGCOMSCTSU


Activities specific to advanced

technology trials Measurements specifically addressing advanced technologies: dynamic wedges, MLC-shaped fields, small fields, etc.

Credentialing using benchmarks (compatibility with QARC maintained where relevant)

Credentialing using phantoms Independent recalculation of dose distributions with Eclipse planning system and RPC “standard” data


Digital Data Submission

>300 institutions have demonstrated ability to submit digital data to ITC

Data-quality QA by ITC; Contour review Dosimetry QA review by

RPC online using RRT RPC compares plan and

phantom data, MD conducts clinical review


• Education

• Evaluate ability to deliver dose

• Improve understanding of protocol

• Reduce deviation rate

Purposes of Credentialing


General Credentialing Process

Feedback to Institution

Previous patients treated with technique Facility questionnaire Knowledge assessment questionnaire Benchmark case or phantom Electronic data submission RPC QA & dosimetry review Clinical review by radiation oncologist

10


Questionnaires

Facility QuestionnaireDocuments equipment Allows evaluation of QA

procedures

Knowledge AssessmentTests physician’s

knowledge of the protocol

11


Brachytherapy Credentialing

Paper- or CT-based benchmark

RPC uses ATC remote review tool

Evaluate single source calculation

Prostate or breast HDR or LDR

QARC used identical methods for prostate LDR

12


3D Conformal Radiation Therapy

(3D CRT)

Evaluate 3D treatment planning process and ability to provide documentation

Conducted by QARC and RPC

~500 institutions credentialed to date

Some through NSABP/RTOG partial breast irradiation protocol

13


IMRT Benchmark for Credentialing

Institution transfers structures to CT data set

Prepares and submits IMRT plan

Demonstrates ability to plan using IMRT

Meet constraints on doses to PTV and OAR

Supplies results of QA measurements


RPC Phantoms

prostate IMRT: 4, incl. prosthesis

thorax SBRT: 3 phantoms, 6 under construction

liver SBRT: 3, incl. motion

H&N IMRT: 25 in service

SRS: 2 in service, others sent by RDS

15


Phantom Mailings by Year

16


IMRT Credentialing

250+ institutions have successfully irradiated an RPC IMRT phantom


Plan vs. Treatment


Phantom ResultsComparison between institution’s plan and delivered dose.

Criteria for agreement: 7% or 4 mm DTA

* 30% of institutions failed H&N phantom on the first attempt

Phantom H&NProstat

eThorax Liver

Irradiations 254 73 30 6Pass 179* 55 17 3Fail 71 9 7 1

Under analysis or at

institution30 6 6 1

Year introduced

2001 2004 2004 2005

Explanations for Failures

ExplanationMinimum # of occurrences

incorrect output factors in TPS 1

incorrect PDD in TPS 1

Software error 1

inadequacies in beam modeling at leaf ends (Cadman, et al; PMB 2002)

14

not adjusting MU to account for dose differences measured with ion chamber

3

errors in couch indexing with Peacock system

3

2 mm tolerence on MLC leaf position 1

setup errors 7

target malfunction 1

21


Credentialing for Lung Protocols

RPC evaluates dose to TLDs Criteria: ± 0.05

Evaluate DTA from film data ± 5 mm at all sides of target

Analysis neglects variation across target RPC has proposed to include evaluation of dose across target

21

22

RPC Lung Phantom

PTV

23


Modifications to Phantoms for IGRT

Presently rely on surface markers and laser alignment

IGRT systems require internal fiducials and/or anatomy for image-based alignment


Evaluation of Heterogeneity Corrections with RPC Thorax Phantom

Convolution/superposition algorithm showing good agreement with measurements

Pencil-beam algorithm showing poor agreement with measurements


Results of Credentialing(closed studies)

Study MajorDeviations

MinorDeviations

Number ofPatients

GOG 165HDR Cervix

Credentialed inst0 15 70

RTOG 95-17HDR & LDR Breast

(all)0 4 100

RTOG 0019LDR Prostate

(values for dose only)0 6 117 reviewed

(total 129 eligible)


Results of Credentialing(closed studies)

Study MajorDeviations

MinorDeviations

Number ofPatients

GOG 165HDR Cervix

Credentialed inst0 15 70

Non-credentialed 57 87 275

RTOG 95-17HDR & LDR Breast

(all)0 4 100

RTOG 0019LDR Prostate

(values for dose only)0 6 117 reviewed

(total 129 eligible)

27


Challenges in Credentialing Need to streamline process Status of institution submission Need additional phantoms

To meet demand To evaluate new techniques (protons, IGRT)

CT benchmarks to be readable by all TPSs

Working to develop: Monte Carlo calculations Improved software to compare plan with film/TLD data

Improved dosimetry systems

27

28


Credentialing Status Inquiry


Status of RPC Preparations for Monitoring Proton Facilities

RPC visited PTC-H during construction to learn about facility design and operation

Visits to PTC-H and to UF/Jacksonville to measure and verify beam output, depth dose characteristics

Irradiated TLD at 3 facilities under more than 30 combinations of energy, field size, depth

Evaluated radiochromic film for use in proton beams

Presently testing BANG® gel & Presage™ dosimeters Evaluating OSL dosimeters

30


challenges in credentialing institutions and participants in advanced technology clinical trials...

Documents

clinical review slide

credentialing institutions

advanced technologies

rpc standard data slide

atc slide

protocol slide

itc dataquality qa

community slide