Radiation Safety in Radiation Safety in BrachytherapyBrachytherapy

KIRUBHA GKIRUBHA G

20092450022009245002

GroupedGrouped

Patient Safety Patient Safety Public SafetyPublic Safety

Radiation Worker SafetyRadiation Worker Safety

SourcesSources Half -Half -Life Life

Energy of Energy of Radiation Radiation

(MeV)(MeV)

GammaGamma

(Ave) (Ave) Beta Beta

Exp.RatExp.Ratee

const., const., x x

(R.cm(R.cm22..hh-1-1.mCi.mCi--

11) )

Air Air Kerma Kerma Rate Rate const., const., k k ((Gy.mGy.m22..hh-1-1. MBq. MBq--

11))

HVL in HVL in

WaterWater

(cm) (cm)

HVL HVL in in

LeadLead

(mm) (mm)

Ra-226Ra-226 1622 yr1622 yr 0.830.83

( 0.05 - 2.45 ) ( 0.05 - 2.45 ) 0.02 - 0.02 - 3.26 3.26

8.25 8.25 0.195 0.195 10.6 10.6 12.0 12.0

Co-60Co-60 5.26 yr5.26 yr 1.25 1.25 (1.17,1.333) (1.17,1.333)

0.31 0.31 13.07 13.07 0.308 0.308 10.8 10.8 11.0 11.0

Cs-137Cs-137 30 yr30 yr 0.662 0.662 0.51-0.51-1.17 1.17

3.26 3.26 0.077 0.077 8.2 8.2 5.55.5

Ir-192Ir-192 73.84 73.84 daysdays

0.38 0.38

( 0.14 -1.06) ( 0.14 -1.06) 0.67 0.67 4.69 4.69 0.111 0.111 6.3 6.3 2.5 2.5

Au-198Au-198 2.7 days2.7 days 0.412 0.412 0.96 0.96 2.38 2.38 0.056 0.056 7.0 7.0 2.5 2.5

I-125I-125 59.4 days59.4 days 0.028 0.028 1.46 1.46 0.034 0.034 2.0 2.0 0.025 0.025

Pd-103Pd-103 17 days17 days 0.021 0.021 1.48 1.48 0.035 0.035 1.0 1.0 0.008 0.008

RadiationRadiation Worker Safety Worker Safety

TimeTimeDistanceDistanceShieldingShielding

• Quality Control of Sources:Quality Control of Sources:IdentificationIdentification

Leakage & ContaminationLeakage & ContaminationDistribution of ActivityDistribution of Activity

Source Strength VerificationSource Strength Verification

Patient Safety Patient Safety IdentificationIdentification

• Date of receipt Date of receipt

• Type of Type of radionuclideradionuclide • Activity on a given date Activity on a given date • Data on leakage & contamination testData on leakage & contamination test• Recommended working life of the source Recommended working life of the source • Physical and chemical composition of the Physical and chemical composition of the

radioactive source radioactive source • Source encapsulation material and Source encapsulation material and

thickness thickness • Active and physical dimensions, etc Active and physical dimensions, etc

LeakageLeakage and and ContaminationContaminationLimit: < 185 BqLimit: < 185 Bq

DistributionDistribution of Activity of Activity

Source Source StrengthStrength VerificationVerification

• Reference Air Kerma RateReference Air Kerma Rate• Air Kerma StrengthAir Kerma Strength

Quality Control of Quality Control of ApplicatorsApplicators

• Integrity of applicators Integrity of applicators • Precision of source position within Precision of source position within

the applicatorthe applicator• Exactness of the orientation of shield Exactness of the orientation of shield

Quality Control of Quality Control of Treatment UnitTreatment Unit

• Mechanical checks Mechanical checks • Electrical checks Electrical checks • Radiation checks as regards clinical Radiation checks as regards clinical

and radiation safety and radiation safety

Mechanical ChecksMechanical Checks

• Coupling between guide-tube and unitCoupling between guide-tube and unit• Coupling between guide tube and Coupling between guide tube and

applicatorapplicator• Coupling between drive cable and sourceCoupling between drive cable and source• Time taken to drive the source to “ON” Time taken to drive the source to “ON”

positionposition• Time taken to drive the source to “OFF” Time taken to drive the source to “OFF”

positionposition• Source guide free of kinksSource guide free of kinks

Electrical ChecksElectrical Checks

Interlocks:Interlocks:1) Treatment room doors1) Treatment room doors

2) Guide tube & Treatment unit2) Guide tube & Treatment unit

3) Applicator & Guide tube3) Applicator & Guide tube

4) Emergency stop button4) Emergency stop button

Source Safe Display:Source Safe Display:1) Treatment “OFF” 1) Treatment “OFF” indicatorindicator

2) Treatment “ON” indicator2) Treatment “ON” indicator

Control Console Display:Control Console Display:1) Treatment “OFF” indicator1) Treatment “OFF” indicator 2) Treatment “ON” indicator2) Treatment “ON” indicator

3) Source ON/OFF indicator3) Source ON/OFF indicator 4) Door interlock indicator4) Door interlock indicator 5) Retrieval of the source 5) Retrieval of the source

indicatorindicator 6) Retrieval of the 6) Retrieval of the dummy indicatordummy indicator

Control Console Function:Control Console Function:1) Power switch1) Power switch 2) Parameter reset switch2) Parameter reset switch 3) Treatment “ON” switch3) Treatment “ON” switch 4) Treatment “OFF” 4) Treatment “OFF”

indicatorindicator 5) Emergency “OFF” switch5) Emergency “OFF” switch 6) Back-up system provided6) Back-up system provided 7) Treatment & elapsed 7) Treatment & elapsed

time displaytime display 8) Multi-channel indexer 8) Multi-channel indexer

functionfunction

Radiation ChecksRadiation Checks

Leakage & ContaminationLeakage & Contamination

Positioning accuracy & UniformityPositioning accuracy & Uniformity

Source Strength VerificationSource Strength Verification

Quality Assurance of TPS: Quality Assurance of TPS: 1) Single 1) Single

sourcesource

2) Multiple source2) Multiple source

Radiation SafetyRadiation Safety

Well calibrated Survey metersWell calibrated Survey meters

Gamma Zone monitorGamma Zone monitor

CCTVCCTV

Properly working Audio-Visual Properly working Audio-Visual

systemsystem

Radiation LevelRadiation Level

• <100 <100 µGy/hr at 5 cm from the µGy/hr at 5 cm from the surface of the containersurface of the container

• <10 <10 µGy/hr at 1 m from the centre µGy/hr at 1 m from the centre of the containerof the container

RadiationRadiation Level Level

Around the InstallationAround the Installation

• On control console < 100 On control console < 100 µGy/hr µGy/hr • Behind the wall <10 Behind the wall <10 µGy/hrµGy/hr

Radiation SafetyRadiation Safety • Receipt of sources, verification and Receipt of sources, verification and

quality control checks quality control checks • Preparation of applicators for use in Preparation of applicators for use in

the patients the patients • Insertion of the applicators into the Insertion of the applicators into the

patient at the operation theatrepatient at the operation theatre• Removal of applicators and sourcesRemoval of applicators and sources• Sterilization of applicators and sourcesSterilization of applicators and sources• Keeping inventory of sourcesKeeping inventory of sources

Exposure to PublicExposure to Public

• During transportation of patients / During transportation of patients / sources in hospital premises sources in hospital premises

• During treatment (in case of manual During treatment (in case of manual loading techniques) loading techniques)

• Loss or accidental mishandling Loss or accidental mishandling

Reported Radiation Reported Radiation Incidents Incidents

• Loss of sources with hospital wastes Loss of sources with hospital wastes • Inadvertent discharge of patientInadvertent discharge of patient• Cremation of dead body with source Cremation of dead body with source

within within • Spread of contamination by cutting Spread of contamination by cutting

applicator with source stuck in applicator with source stuck in

Necessary to ensure safe work Necessary to ensure safe work practices at all the levels. practices at all the levels.

Safety of SourcesSafety of Sources• Sources should be stored in a secure room Sources should be stored in a secure room

with adequate shieldingwith adequate shielding• Storage should be close to the location in Storage should be close to the location in

which the sources are preparedwhich the sources are prepared• Easily identify the different types of Easily identify the different types of

sources sources • Log book should be maintained Log book should be maintained • Carriers used for transporting the sources: Carriers used for transporting the sources:

adequate shielding and good mobility adequate shielding and good mobility

PatientPatient Care Care • Separate treatment ward with adequate Separate treatment ward with adequate

shielding on all sides and at the entrance shielding on all sides and at the entrance • Distance between two patients should be Distance between two patients should be

such that the dose contribution from one such that the dose contribution from one patient to the other is negligible patient to the other is negligible

• A mobile lead shield may be provided near A mobile lead shield may be provided near each patient to minimize the dose to each patient to minimize the dose to attending staff attending staff

• A sign should be posted on the door A sign should be posted on the door warning of the radiation hazard, in warning of the radiation hazard, in accordance with the regulatory requirement accordance with the regulatory requirement

• Entry by family members should be Entry by family members should be restricted restricted

Cont..Cont..

• Radiation monitor with audio system should Radiation monitor with audio system should always be kept near the entrance door to ensure always be kept near the entrance door to ensure inadvertent movement of sources from the inadvertent movement of sources from the treatment room treatment room

• The implanted patient should be surveyed and The implanted patient should be surveyed and the radiation level at 1m should be notedthe radiation level at 1m should be noted

• After removal, the sources should be counted After removal, the sources should be counted and verified and verified

• For manual afterloading applications: use a For manual afterloading applications: use a mobile shield at the time of insertion, treatment mobile shield at the time of insertion, treatment and removal of sources from the patient. and removal of sources from the patient.

Cont..Cont..

• To transport implanted patients, only To transport implanted patients, only trained hospital staff should be allowed. trained hospital staff should be allowed.

• Crowded hallways as well as areas with Crowded hallways as well as areas with children should be avoided.children should be avoided.

• Patient should never be left unattended in Patient should never be left unattended in unsecured areas.unsecured areas.

• The patient should be discharged only if The patient should be discharged only if the radiation level is within permissible the radiation level is within permissible limitslimits

• The patient should be informed of the The patient should be informed of the nature of radiation hazard and how long nature of radiation hazard and how long they should practice reasonable they should practice reasonable precautions to minimize exposure to precautions to minimize exposure to others. others.

Cont..Cont..

THANK YOUTHANK YOU