Use of a second-dose calculation algorithm to check dosimetric parameters for the dose distribution of a first-dose calculation algorithm for lung SBRT plans

作     者：Tsuruta, Yusuke Nakamura, Mitsuhiro Miyabe, Yuki Nakata, Manabu Ishihara, Yoshitomo Mukumoto, Nobutaka Akimoto, Mami Ono, Tomohiro Yano, Shinsuke Higashimura, Kyoji Matsuo, Yukinori Mizowaki, Takashi Hiraoka, Masahiro 

作者机构：Kyoto Univ Hosp Div Clin Radiol Serv Kyoto 6068507 Japan Kyoto Univ Grad Sch Med Dept Radiat Oncol & Image Appl Therapy Kyoto 6068507 Japan 

出 版 物：《PHYSICA MEDICA-EUROPEAN JOURNAL OF MEDICAL PHYSICS》 (医学物理)

年 卷 期：2017年第44卷

页      面：86-95页

核心收录：

学科分类：1009[医学-特种医学] 10[医学] 

基　　金：Ministry of Education, Culture, Sports, Science, and Technology, of Japan Grants-in-Aid for Scientific Research Funding Source: KAKEN 

主　　题：Monitor unit verification Dose calculation algorithm Independent secondary TPS Lung SBRT 

摘      要：Purpose: To verify lung stereotactic body radiotherapy (SBRT) plans using a secondary treatment planning system (TPS) as an independent method of verification and to define tolerance levels (TLs) in lung SBRT between the primary and secondary TPSs. Methods: A total of 147 lung SBRT plans calculated using X-ray voxel Monte Carlo (XVMC) were exported from iPlan to Eclipse in DICOM format. Dose distributions were recalculated using the Acuros XB (AXB) and the anisotropic analytical algorithm (AAA), while maintaining monitor units (MUs) and the beam arrangement. Dose to isocenter and dose-volumetric parameters, such as D-2, D-50, D-95 and D-98, were evaluated for each patient. The TLs of all parameters between XVMC and AXB (TLAXB) and between XVMC and AAA (TLAAA) were calculated as the mean +/- 1.96 standard deviations. Results: AXB values agreed with XVMC values within 3.5% for all dosimetric parameters in all patients. By contrast, AAA sometimes calculated a 10% higher dose in PTV D-95 and D-98 than XVMC. The TLAXB and TLAAA of the dose to isocenter were -0.3 +/- 1.4% and 0.6 +/- 2.9%, respectively. Those of D-95 were 1.3 +/- 1.8% and 1.7 +/- 3.6%, respectively. Conclusions: This study quantitatively demonstrated that the dosimetric performance of AXB is almost equal to that of XVMC, compared with that of AAA. Therefore, AXB is a more appropriate algorithm for an independent verification method for XVMC. (C) 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.