Sirinya Ruangchan.. Evaluation of two quality control softwares in generating the dose volume histograms for volumetric modulated Arc radiotherapy plan in head region. Master's Degree(Medical Physics). Mahidol University. Mahidol University Library and Knowledge Center. : Mahidol University, 2013.
Evaluation of two quality control softwares in generating the dose volume histograms for volumetric modulated Arc radiotherapy plan in head region
Abstract:
This study was aimed to evaluate the dose volume histogram (DVHs) between COMPASS and 3DVH software for 3D patient-specific QA in VMAT technique used for head region. The MatriXX characteristics were studied before the clinical use. The DVHs of COMPASS and 3DVH software were evaluated for basic and advanced clinical application. The homogeneous phantom with four fields box technique plan was employed in the basic clinical application. For the advanced clinical application, 15 VMAT treatment plans targeting the head region were investigated. The treatment plans were transferred to MatriXX and ArcCHECK for measurement and to generated the DVHs in COMPASS and 3DVH software, respectively. The DVHs and percent gamma pass were compared with calculations from the Eclipse treatment planning system (TPS) according to dose specified in ICRU 83 for PTV and OARs. The study of the MatriXX characteristics illustrated the data provided were suitable for using in the clinic. With regard to the basic clinical application in homogeneous phantom with four fields box technique, COMPASS and 3DVH software showed comparable dose outcomes between the measurement and calculation from TPS for D98%, D95%, D50%, D2% and Dmean in PTV. For the advanced clinical application in 15 VMAT plans, the mean percent dose difference from TPS for the COMPASS of D98%, D95%, D50%, D2% and Dmean in PTV were -4.10±3.88%, 2.21±3.13%, 1.26±2.35%, 3.25±2.32% and 0.96±2.19%, respectively. The mean percent dose showed a difference of D98%, D95%, D50%, D2% and Dmean in PTV for the 3DVH were -8.34±4.32%, - 7.90±4.02%, -4.06±2.45%, -0.19±2.27% and -4.23±2.12%, respectively. The TPS mean percent dose difference in OARs of both QA softwares showed a large variation with the highest difference of 11% in COMPASS software and 6.66% in 3DVH software. The percent of gamma pass (3%/3mm) of COMPASS, 3DVH and ArcCHECK were 99.19± 0.49, 94.98±3.49 and 98.87±0.84, respectively. The difference of percent pass in 3DVH was lower than ArcCHECK because of 3DVH software estimated 3D dose using PDP files while ArcCHECK displayed planar dose distribution. A weak correlation between percent gamma pass and dose in patient were observed. So, the pre-treatment verifications with DVHs analysis are recommended. The COMPASS and 3DVH software illustrated that both of QA software can be used in 3D pretreatment verification.