Comparison of four commercial devices for RapidArc and sliding window IMRT QA

Abstract

For intensity‐modulated radiation therapy, evaluation of the measured dose against the treatment planning calculated dose is essential in the context of patient‐specific quality assurance. The complexity of volumetric arc radiotherapy delivery attributed to its dynamic and synchronization nature require new methods and potentially new tools for the quality assurance of such techniques. In the present study, we evaluated and compared the dosimetric performance of EDR2 film and three other commercially available quality assurance devices: IBA I'MatriXX array, PTW Seven29 array and the Delta 4 array. The evaluation of these dosimetric systems was performed for RapidArc and IMRT deliveries using a Varian NovalisTX linear accelerator. The plans were generated using the Varian Eclipse treatment planning system. Our results showed that all four QA techniques yield equivalent results. All patient QAs passed our institutional clinical criteria of gamma index based on a 3% dose difference and 3 mm distance to agreement. In addition, the Bland‐Altman analysis was performed which showed that all the calculated gamma values of all three QA devices were within 5% from those of the film. The results showed that the four QA systems used in this patient‐specific IMRT QA analysis are equivalent. We concluded that the dosimetric systems under investigation can be used interchangeably for routine patient specific QA.PACS numbers: 87.55.Qr, 87.56.Fc

Total Body Irradiation using VMAT (RapidArc): A Planning Study of a novel treatment delivery method

“…17 However we do plan to delivery and verify the plan using thermoluminescence dosimetry on an anthropomorphic phantom once it has been purchased.…”

A retrospective analysis for patient-specific quality assurance of volumetric-modulated arc therapy plans

“…1 However, owing to the completely dynamic implementation and the complexity of treatment delivery, patient-specific dosimetric verifications for VMAT plans are required before clinical treatments. 8 Many types of dosimeters have been used for patientspecific quality assurance (QA), such as ion chamber, film, 9,10 2-dimensional (2D) diode or ion chamber matrix detectors, [10][11][12][13][14] electronic portal imaging devices, 15 gel dosimetry, 16 and 3D diode arrays. 17,18 3D diode arrays are easy to use and provide 3D dose distributions and QA results, while measurements are being performed.…”

Study of feasibility of portal dosimetry in comparison with ImatriXX 2-D array system for IMRT and Rapid arc patient specific QA.

“…An easy to perform and reliable QA device plays an important role to reduce the labor and time consumption of medical physicists in radiation oncology. Many studies were published regarding the use of 2-D array detectors and aSi1000 EPIDs for quality assurance of IMRT and rapid arc patient specific plans (12)(13)(14)(15). This study provides comparison results of patient specific IMRT and rapid arc plans using aSi1000 portal dosimetry and ImatriXX 2-D array system.…”