Kazuo Tarutani1,2, Masao Tanooka1,3, Hiroshi Doi1,4, Masayuki Fujiwara1, Masaki Miyashita2, Kazufumi Kagawa2, Norihiko Kamikonya2, Koichiro Yamakado1. 1. Department of Radiology, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo 663-8501, Japan. 2. Japan Organization of Occupational Health and Safety Kansai Rousai Hospital, 3-1-69, Inabaso, Amagasaki, Hyogo 660-8511, Japan. 3. Department of Radiotherapy, Takarazuka City Hospital, 4-5-1, Kohama, Takaraduka, Hyogo 665-0827, Japan. 4. Department of Radiation Oncology, Kindai University Faculty of Medicine, 377-2, Ohnohigashi, Sayama, Osaka 589-8511, Japan.
Abstract
AIM: We sought to improve error detection ability during volume modulated arc therapy (VMAT) by dividing and evaluating the treatment plan. BACKGROUND: VMAT involves moving a beam source delivering radiation to tumor tissue through an arc, which significantly decreases treatment time. Treatment planning for VMAT involves many parameters. Quality assurance before treatment is a major focus of research. MATERIALS AND METHODS: We used an established VMAT prostate treatment plan and divided it into 12° × 30° sections. In all the sections, only image data that generated errors in one segment and those that were integrally acquired were evaluated by a gamma analysis. This was done with five different patient plans. RESULTS: The integrated image data resulting from errors in each section was 100% (tolerance 0.5 mm/0.5%) in the gamma analysis result in all image data. Division of the treatment plans produced a shift in the mean value of each gamma analysis in the cranial, left, and ventral directions of 94.59%, 98.83%, 96.58%, and the discrimination ability improved. CONCLUSION: The error discrimination ability was improved by dividing and verifying the portal imaging.
AIM: We sought to improve error detection ability during volume modulated arc therapy (VMAT) by dividing and evaluating the treatment plan. BACKGROUND: VMAT involves moving a beam source delivering radiation to tumor tissue through an arc, which significantly decreases treatment time. Treatment planning for VMAT involves many parameters. Quality assurance before treatment is a major focus of research. MATERIALS AND METHODS: We used an established VMAT prostate treatment plan and divided it into 12° × 30° sections. In all the sections, only image data that generated errors in one segment and those that were integrally acquired were evaluated by a gamma analysis. This was done with five different patient plans. RESULTS: The integrated image data resulting from errors in each section was 100% (tolerance 0.5 mm/0.5%) in the gamma analysis result in all image data. Division of the treatment plans produced a shift in the mean value of each gamma analysis in the cranial, left, and ventral directions of 94.59%, 98.83%, 96.58%, and the discrimination ability improved. CONCLUSION: The error discrimination ability was improved by dividing and verifying the portal imaging.
Authors: Anton Mans; Peter Remeijer; Igor Olaciregui-Ruiz; Markus Wendling; Jan-Jakob Sonke; Ben Mijnheer; Marcel van Herk; Joep C Stroom Journal: Radiother Oncol Date: 2010-01-19 Impact factor: 6.280
Authors: Markus Wendling; Leah N McDermott; Anton Mans; Jan-Jakob Sonke; Marcel van Herk; Ben J Mijnheer Journal: Med Phys Date: 2009-07 Impact factor: 4.071