Implementation of a quality assurance program for computerized treatment planning systems

Abstract

In the present investigation, the necessary tests for implementing a quality assurance program for a commercial treatment planning system (TPS), recently installed at Sao Paulo University School of Medicine Clinicas Hospital-Brazil, was established and performed in accordance with the new IAEA publication TRS 430, and with AAPM Task Group 53. The tests recommended by those documents are classified mainly into acceptance, commissioning (dosimetric and nondosimetric), periodic quality assurance, and patient specific quality assurance tests. The recommendations of both IAEA and AAPM documents are being implemented at the hospital for photon beams produced by two linear accelerators. A Farmer ionization chamber was used in a 30 x 30 x 30 cm3 phantom with a dose rate of 320 monitor unit (MU)/min and 50 MU in the case of the dosimetric tests. The acceptance tests verified hardware, network systems integration, data transfer, and software parameters. The results obtained are in good agreement with the specifications of the manufacturer. For the commissioning dosimetric tests, the absolute dose was measured for simple geometries, such as square and rectangular fields, up to more complex geometries such as off-axis hard wedges and for behavior in the build up region. Results were analysed by the use of confidence limit as proposed by Venselaar et al. [Radio Ther. Oncol. 60, 191-201 (2001)]. Criteria of acceptability had been applied also for the comparison between the values of MU calculated manually and MU generated by TPS. The results of the dosimetric tests show that work can be reduced by choosing to perform only those that are more crucial, such as oblique incidence, shaped fields, hard wedges, and buildup region behavior. Staff experience with the implementation of the quality assurance program for a commercial TPS is extremely useful as part of a training program.

An institutional experience of quality assurance of a treatment planning system on photon beam

“…In this study, we commissioned Varian Eclipse TM v7.5 TPS in accordance with the procedure of the IAEA TRS-430 for clinical photon beams. The accuracy of the dosimetric calculation of Eclipse TM TPS v7.5.18 has been implemented and reported in detail by Camargo et al 21 It was reported that the most critical difference occurs for oblique incidence, oblique incidence off axis, shaped fields and off axis wedge. The QA of Eclipse TM TPS v7.3.10 has been reported in detail by Jamema et al 20 According to that report, it was determined that oblique incidence calculation does not show a variation outside the tolerance limits.…”

“…A number of authors [20][21][22][23] have implemented dosimetric and non-dosimetric tests of QA procedure into TPS with the guidance of the IAEA TRS 430 report. These authors have reported that the most critical difference occurred for oblique incidence, oblique incidence-off axis, shaped fields and off axis-wedged.…”

Commissioning and Comprehensive Quality Assurance of commercial 3D Treatment Planning System using IAEA Technical Report Series — 430

“…The accuracy of the dosimetric calculation of Eclipse TM TPS v7.5.18 has been assessed and reported in detail by Camargo et al 7 . In this work, we focused both on dosimetric and non-dosimetric tests for commissioning and QA of Eclipse™ TPS.…”

“…6 Image reconstruction A. 7 2-D and 3-D display The purpose of the present study is to report the commissioning and QA of TPS using TRS 430 1 guidelines and to develop a QA program specific to our department. …”

Verificação 3D da distribuição da dose em radiocirurgia estereotáxica através de simulação Monte Carlo e dosimetria por ressonância magnética nuclear

“…Com o decorrer dos anos, o desenvolvimento da tecnologia proporcionou que se pudessem obter imagens por tomografia computarizada, melhorando, assim, a delimitação dos volumes do tratamento. Os sistemas de planejamento computadorizados incluem softwares e hardwares que possibilitam o uso de imagens anatômicas tridimensionais dos pacientes para realização do planejamento radioterápico, permitindo correções de heterogeneidades e cálculos de dose e distribuições de dose em três dimensões com maior rapidez e precisão(Podgorsak et al, 2005; IAEA, 2004) Camaro et al, 2007;Able et al, 2005;Mijnheer, 2004)…”