PROFORMA ACCEPTANCE / QUALITY ASSURANCE TESTS OF REMOTE AFTERLOADING BRACHYTHERAPY UNIT

Transcription

1 RP&AD /Remote QA/ 01 PROFORMA FOR ACCEPTANCE / QUALITY ASSURANCE TESTS OF REMOTE AFTERLOADING BRACHYTHERAPY UNIT BHABHA ATOMIC RESEARCH CENTRE Radiological Physics & Advisory Division CT & CRS Building, Anushaktinagar Mumbai

2 1 1. General Information ACCEPTANCE / QUALITY ASSURANCE TESTS OF REMOTE AFTERLOADING BRACHYTHERAPY UNIT 1.1 Name and Address of the Institution: (Include Pin Code) Fax: Tel.: Staff (a) Radiotherapist(s) Sr. No. Name Qualification(s) Experience (b) Medical Physicist(s) / Radiological Safety Officer: Sr. No. Name Qualification(s) Experience 1.3 Treatment Unit Type : LDR / MDR / HDR / PDR Make, Model & Number : Maximum capacity of the Unit : MBq/GBq (mci/ci) Radionuclide : 137 Cs / 192 Ir / 60 Co 1

3 2 Physical dimensions of : Length (mm): ; Dia. (mm): source(s) No. of sources : Total & individual activity : µgy/h at 1m (mci) of sources (as quoted by the supplier) : µgy/h at 1m (mci) Dummy sources provided? : Yes / No No. of channels : Max. no. of channels used : Simultaneously Method of source transfer : Pneumatic / Drive cable / Stepping Motor/ between applicator & safe Treatment mode : Fixed / Programmable/ Pulsed /... Method of source retraction : Gravity/ Back-up Battery/ Pneumatic / in the event of power failure Special features (if any) : Nurse's station provided? : Yes / No Plan approved on (date) : Source(s) loaded on (date) : Source(s) loaded by : 2

4 3 2. QA Tests : Mechanical 2.1 Functioning of sensors like : Satisfactory / No pressure, torque, optical 2.2 Coupling between guide- : Satisfactory / No tube and unit 2.3 Coupling between guide- : Satisfactory / No tube and applicator 2.4 Coupling between drive : Satisfactory / No cable and source 2.5 Time taken to drive the source to : sec "ON" position 2.6 Time taken to withdraw the source to : sec "OFF" position 2.7 Source guide free of kinks? : Yes/No 2.8 Mechanical integrity of applicators & : Acceptable / Not acceptable position of shield, if any 3. QA Tests : Electrical 3.1 Interlocks Treatment Room Door(s) Guide Tube & Treatment Unit Applicator & Guide Tube Emergency stop button to interrupt the irradiation 3.2 Source Safe Display Treatment "OFF" indicator Treatment "ON" indicator 3

5 4 3.3 Control Console Display Treatment "OFF" indicator Treatment "ON" indicator Source ON/OFF indicator Door interlock indicator Retrieval of the source indicator Retrieval of the dummy indicator 3.4 Control Console Function Power switch Parameter reset switch Treatment `ON switch Treatment `OFF switch Emergency `OFF switch Treatment and elapsed time display counters Multi-channel indexer function and sequence displays Back-up system(s) 4

6 5 4. QA Tests : Radiation (attach relevant data for evaluation) 4.1 Leakage and Contamination ( Limit: 200 Bq) (Using a wet swipe measure the maximum removable activity on the surface of the source / source holder) Removable activity on Source / Source holder : Bq Contamination check done on (date) : 4.2 Positioning Accuracy and Uniformity (Tolerance: ± 1 mm) (use autoradiograph / radiograph wherever required) Coincidence between dummy : mm and active source positions Accuracy of source position within the : mm applicator Reproducibility of dummy source position : mm 4.3 Temporal Accuracy (Tolerance: ± 1 %) Timer error : Timer linearity : End error : sec ('or' %) 4.4 Source Strength Verification Quoted source strength (as on ) : µgy. h -1 at 1m ( GBq / Ci ) Measured source strength (as on ) : µgy. h -1 at 1m ( GBq / Ci ) Deviation between specified : % and measured source strength (Tolerance: ± 3%) Deviation between measured : % mean and individual source strength (Tolerance: ± 5%) In a separate sheet explain the procedure and the instrument(s) used. In case of multiple sources, give the average source strength and the variation among individual sources. 5

7 6 5. QA Tests: Treatment Planning System 5.1 Digitizer and Localization Software: (Tolerance: 3% or 1mm) Accuracy of digitization of : Point co-ordinates Accuracy of data transfer from : orthogonal radiographs 5.2 Calculation Algorithm: Source specification required for TPS : mci / mg.ra.eq./ MBq / Ref. Air. Kerma Rate Initial activity quoted by the supplier : Current activity (with date) : Factor used to convert quoted source strength for TPS input : Agreement of source decay correction : Agreement between TPS and : published/manual calculation for single source, at relevant points Agreement for multiple source loading : (Specify the procedure and the result) (Tolerance: 3% or 1 mm) 6. QA Tests: Radiation Safety 6.1 Gamma Zone Monitor: Provided? Working? : Yes / No : Yes / No 6.2 CCTV Working? : Yes / No 6.3 Unit Leakage Measure the dose rate on top, bottom and four sides of the container at 5 cm from the surface and one meter from the centre of source storage for source 'OFF condition: Measured dose rate (µgy.h -1 ) at 5cm : from the surface of the source storage (Tolerance: 100 µgy.h -1 ) Measured dose rate (µgy.h -1 ) at 1 m : from the centre of the source storage (Tolerance: 10 µgy.h -1 ) Note: The above tolerance limits are applicable when the unit is loaded with the maximum capacity. 6

8 Survey of the Installation: In the Figure below, mark the occupancy on all sides, above and below the installation and measure the maximum dose rates at these locations, with the applicator loaded with maximum source activity and kept at the centre of the treatment table. Minimum locations recommended for radiation protection survey of the installation are: A, A, B, B Just outside the four walls of the installation at the level of source 'S' C Roof of the installation, at the level of source 'S' D Just outside entrance door E &F At the level of air conditioners G - Entrance to control panel (S : Source position ; CP : Control Panel ) F E A.C. A A.C. B S B F l o o r L e v e l R o o f L e v e l C D C.P A Section Across AA G Fig. 1- Typical Layout of a Remote Afterloading Brachytherapy Facility 7

9 Source Activity (GBq/Ci) during survey : Instrument(s) used for survey : Measured dose rate (µgyh -1 ) at positions marked in Fig. 1: A A B B C D E F G Note: The quoted dose rate should be the maximum measured in the specified direction. 7. Instruments Used for Measurement Sr.No. Type Make &Model Cal. Factor (& Ambient conditions) Date of Calibration Calibrated at Checked by Measured by Signature : Signature : Name : Name : Designation : Designation : Date : Date : : Instrument(s) used for survey : 8