PURPOSE This work investigates the use of receiver operating characteristic (ROC) methods in patient specific IMRT quality assurance (QA) in order to determine unbiased methods to set threshold criteria for γ-distance to agreement measurements. METHODS A group of 17 prostate plans was delivered as planned while a second group of 17 prostate plans was modified with the introduction of random m...

The purpose of this study is to evaluate the overall accuracy of intensity-modulated radiation therapy (IMRT) and RapidArc delivery using both flattening filter (FF) and flattening filter-free (FFF) modalities based on test cases developed by AAPM Task Group 119. Institutional confidence limits (CLs) were established as the baseline for patient specific treatment plan quality assurance (QA). Th...

Accuracy and precision of leaf positioning in multileaf collimators (MLCs) are significant factors for the accuracy of IMRT treatments. This study aimed to inves-tigate the accuracy and repeatability of the MLC leaf positioning via the DAVID invivo dosimetric system for dynamic and static MLC systems. The DAVID system was designed as multiwire transmission ionization chamber which is placed in ...

The control loop in the Varian DMLC system (V4.8) requires approximately 65 msec to monitor and halt the irradiation of a segment, causing an "overshoot" effect: the segment ends on a fractional monitor unit larger than that planned. As a result, the actual MU delivered may differ from that planned. In general, for step-and-shoot treatments, the first segment receives more, the last receives le...

PURPOSE New devices for IMRT and VMAT QA are continually becoming available. Despite the availability of these devices they are underutilized for routine mechanical QA. In this work we take advantage of the cylindrical geometry of the Arc Check phantom to perform tests that are an integral part of commissioning and routine QA. METHODS The Arc Check is a cylindrical phantom with a diameter of ...

PURPOSE To explore site- and clinician-level factors associated with protocol violations requiring real-time-review (RTR) resubmission in a multicenter clinical trial to help tailor future quality assurance (QA) protocols. METHODS AND MATERIALS RAVES (Radiation Therapy-Adjuvant vs Early Salvage) (Trans-Tasman Radiation Oncology Group 08.03) is a randomized trial comparing adjuvant with early ...

PURPOSE Consistency verification between the data from treatment planning system (TPS), record and verification system (R&V), and delivered recorder with visual inspection is time consuming and subject to human error. The purpose of this work is to develop a software tool to automatically perform such verifications. METHODS Using Microsoft visual C++, a quality assurance (QA) tool was develop...