180 likes | 367 Views
RADIATION PROTECTION IN RADIOTHERAPY. IAEA Training Material on Radiation Protection in Radiotherapy. Part 11: Brachytherapy PRACTICAL EXERCISE. IAEA Post Graduate Educational Course Radiation Protection and Safe Use of Radiation Sources. Objectives.
E N D
RADIATION PROTECTION IN RADIOTHERAPY IAEA Training Material on Radiation Protection in Radiotherapy Part 11: Brachytherapy PRACTICAL EXERCISE IAEA Post Graduate Educational Course Radiation Protection and Safe Use of Radiation Sources
Objectives • To be familiar with the brachytherapy process • To be able to discuss methods for brachytherapy planning and dosimetry • To understand the optimization of dose delivery to the target by choosing appropriate isotopes and delivery techniques • To understand the implications of the above for radiation safety Part 11, Practical 1
Part 11: Good Practice in Brachytherapy IAEA Training Material on Radiation Protection in Radiotherapy Practical 1: QA for HDR brachytherapy IAEA Post Graduate Educational Course Radiation Protection and Safe Use of Radiation Sources
High Dose Rate Brachytherapy • Most modern brachytherapy is delivered using HDR • Outpatient procedure • Optimization possible Part 11, Practical 1
Optimization of dose distribution • Can be achieved by altering the dwell times in all positions • High activity source (>30GBq 192-Ir) • Complex movement Part 11, Practical 1
Contents + Objective • Quality assurance of the brachytherapy unit: • Source • Movement/localization • Timers • Associated equipment • Radiation monitors/safety equipment • Be able to perform tests for the above Part 11, Practical 1
Check of the source • Activity • Well chamber • Phantom • In-air jig • Integrity of the source • Wipe test typically performed by the company Courtesy Nucletron Part 11, Practical 1
Additional issues • Ensure calibration of dosimetric devices is traceable to appropriate standard • Verify decay correction in treatment planning Part 11, Practical 1
Verification of movement • Check new source can move through all applicators and catheters in use (no rough edges, no difference in size) • Check dummy source (used for localization of the applicators and for motion test prior to treatment) and real source have identical geometry (if applicable) Part 11, Practical 1
Check positioning accuracy • Verify different distances: • jigs available • may be possible via video camera • film allows to obtain permanent record and use different applicators Part 11, Practical 1
Verification of source movement • Measurement jig • Film cassette for autoradiograph MDS Nordion Measurement jig allows introduction of active source and dummy Nucletron Part 11, Practical 1
Associated issues • Determine correct length of needles and catheters • Check diagnostic X Ray equipment for distortion • Verify digitizer and printer scale and dimensions Part 11, Practical 1
Timer • Both independent timers MUST be checked Part 11, Practical 1
Associated equipment • Safety Interlocks • Mobile shielding • Emergency safe • Manual source retraction • Compare hard copies and treatment records are correct Part 11, Practical 1
Check all applicators, templates and spacers in use for integrity Part 11, Practical 1
Radiation monitors • Working? • Accurate reading? • Check sources? • Traceable calibration? • Any interlocks or alarms connected working? Part 11, Practical 1
Questions? Let’s get started... Part 11, Practical 1