Predicting Delivery Error Using a DICOM-RT Plan for Volumetric Modulated Arc Therapy

作     者：Hideharu Miura Masao Tanooka Masayuki Fujiwara Yasuhiro Takada Hiroshi Doi Soichi Odawara Kengo Kosaka Norihiko Kamikonya Shozo Hirota 

作者机构：Department of Radiological Technology Hyogo College of Medicine College Hospital Hyogo Mukogawa-cho Nishinomiya City Hyogo Japan Department of Radiology Hyogo College of Medicine 1-1 Mukogawa-cho Nishinomiya City Hyogo Japan 

出 版 物：《International Journal of Medical Physics, Clinical Engineering and Radiation Oncology》 (医学物理学、临床工程、放射肿瘤学（英文）)

年 卷 期：2014年第3卷第2期

页      面：82-87页

学科分类：1002[医学-临床医学] 100214[医学-肿瘤学] 10[医学] 

主　　题：Volumetric-Modulated Arc Therapy DICOM-RT Plan Patient-Specific QA Radiotherapy Planning Computer-Assisted 

摘      要：The purpose of this study was to investigate the prediction of mechanical error using DICOM-RT plan parameters for volumetric modulated arc therapy (VMAT). We created plans for gantry rotation arcs of 360° and 180° (full-arc and half-arc VMAT) for six maxillary sinus cancer cases using a Monaco treatment planning system, and delivered the doses with a linear accelerator. We calculated DICOM-RT plan parameters, including gantry, multileaf collimator (MLC) positions and Monitor Units (MU). We compared plans with regard to gantry angle per MU (degrees/MU) and MLC travel per MU (mm/MU) for each segment. Calculated gantry angle/MLC position speeds and errors were evaluated by comparison with the log file. On average, the half-arc VMAT plan resulted in 47% and 35% fewer degrees/MU and mm/MU than the full-arc VMAT plan, respectively. The root mean square (r.m.s.) gantry and MLC speeds showed a linear relationship with calculated degrees/MU and mm/MU, with coefficients of determination (R2) of 0.86 and 0.72, respectively. The r.m.s. gantry angle and MLC position errors showed a linear relationship with calculated degrees/MU and mm/MU with R2 of 0.63 and 0.76, respectively. Deviations from plan parameters were related to mechanical error for VMAT, and provided quantitative information without the need for VMAT delivery. These parameters can be used in the selection of treatment planning.