P22. Evaluation and implementation of the module myQA Machines for a standard Elekta Synergy accelerator, with setup of acceptance criteria according to the guidelines defined by the decision of the ANSM of July 27th, 2007, and setting in routine

Abstract

Introduction myQA platform and devices is a computer program hosting applications developed by IBA. It provides different modules for dosimetry qality assurance (QA) including machine QA, patient QA, and radiotherapy QA. This project regards myQA Machines which provides a complete set of functions to plan, perform, analyze and document quality assurance of treatment units, imaging devices and their accessories. All QA activities are based on customizable protocols. The objective of this project is to implement a protocol according to ANSM decision of July 27th, 2007 in order to evaluate the application myQA Machines for a setting in routine in the service. Methods We use an Elekta Synergy MLC80 accelerator delivering X-ray beams of 6 and 18 MV and electron beams from 6 to 18 MeV. It has a system of Portal and CBCT imagery. In myQA Machines, there are two possible types of tests: Generic tests , when the measurements are carried out without the software and results are manually entered, and Plugin tests , when the complete QA procedure is performed with the software using the multi detector MatriXX for example. The results of dosimetry and MLC tests will be compared respectively with those obtained in reference conditions (water phantom standard MP3 PTW) and with the Aquilab solution. A study of influence of mechanical, physical and dosimetric parameters of the accelerator is carried out in the aim of evaluating the performances and the limits of the system myQA Machines as well as defined acceptability criteria. Results The template related to the QA according to ANSM decision is operational on myQA Machines software. Results of Plugin tests are conforms. The largest difference between constancy measurements and references for homogeneity and symmetry, of all the beams available on the machine, is lower than 1%. The study on the sensitivity of the system shows the importance to choose the tolerances well because a variation of more than 1 mm in the centering of MatriXX induces a non-conformity of at least one of the controlled parameters. Conclusion The application myQA Machines is operational for the quality controls on machines. The analysis of QA results and sensitivity study’s results will enable us to determine the feasibility, reliability and adaptability of myQA Machines software for a setting in routine in an external service of radiotherapy. This implementation would make it possible to have control of data by connecting all the applications of QA on a single platform.