AAPM Medical Physics Practice Guideline 8.a.: Linear accelerator performance tests.

Koren Smith,Lynne A Fairobent,Peter Balter,John Duhon,Christopher F Serago,David L Vassy,Robin A Miller,Gerald A White

doi:10.1002/acm2.12080

Abstract

PurposeThe purpose of this guideline is to provide a list of critical performance tests in order to assist the Qualified Medical Physicist (QMP) in establishing and maintaining a safe and effective quality assurance (QA) program. The performance tests on a linear accelerator (linac) should be selected to fit the clinical patterns of use of the accelerator and care should be given to perform tests which are relevant to detecting errors related to the specific use of the accelerator.MethodsA risk assessment was performed on tests from current task group reports on linac QA to highlight those tests that are most effective at maintaining safety and quality for the patient. Recommendations are made on the acquisition of reference or baseline data, the establishment of machine isocenter on a routine basis, basing performance tests on clinical use of the linac, working with vendors to establish QA tests and performing tests after maintenance.ResultsThe recommended tests proposed in this guideline were chosen based on the results from the risk analysis and the consensus of the guideline's committee. The tests are grouped together by class of test (e.g., dosimetry, mechanical, etc.) and clinical parameter tested. Implementation notes are included for each test so that the QMP can understand the overall goal of each test.ConclusionThis guideline will assist the QMP in developing a comprehensive QA program for linacs in the external beam radiation therapy setting. The committee sought to prioritize tests by their implication on quality and patient safety. The QMP is ultimately responsible for implementing appropriate tests. In the spirit of the report from American Association of Physicists in Medicine Task Group 100, individual institutions are encouraged to analyze the risks involved in their own clinical practice and determine which performance tests are relevant in their own radiotherapy clinics.

Highlights

A comprehensive quality management program in a radiotherapy clinic utilizing external beam radiation therapy will include performance testing of a linear accelerator
The purpose of this guideline is to provide a list of critical performance tests in order to assist the Qualified Medical Physicist (QMP) in establishing and maintaining a safe and effective quality assurance (QA) program that matches the clinical use of the accelerator
A risk assessment was performed on tests from current task group reports on linac QA following the failure mode and effects analysis (FMEA) approach.[8,9,10]

Summary

| INTRODUCTION

A comprehensive quality management program in a radiotherapy clinic utilizing external beam radiation therapy will include performance testing of a linear accelerator (linac). The intended users of this report are QMPs who are conducting linac performance tests or those that are designing a QA program for linacs and seek to understand the critical tests needed to detect errors and ensure safe and high quality external beam radiation therapy delivery. A risk assessment was performed on tests from current task group reports on linac QA following the failure mode and effects analysis (FMEA) approach.[8,9,10] Reviewed tests were primarily from the report of AAPM Task Group 142, “Task Group 142 report: Quality assurance of medical accelerators”.3. Differences in ranking order exist in the mid-level and lower ranking tests

40 Jaw position indicators

10 | SUMMARY

Findings

Dynamic delivery control