Comparison of Pencil-beam, Collapsed-cone and Monte-Carlo Algorithms in Radiotherapy Treatment Planning for 6-MV photons

作     者：Kim, Sung Jin Kim, Sung Kyu Kim, Dong Ho 

作者机构：Yeungnam Univ Dept Phys Gyongsan 712749 South Korea Eulji Univ Hosp Dept Radiat Oncol Daejeon 302799 South Korea Yeungnam Univ Dept Radiat Oncol Coll Med Taegu 705717 South Korea 

出 版 物：《JOURNAL OF THE KOREAN PHYSICAL SOCIETY》 (韩国物理学会志)

年 卷 期：2015年第67卷第1期

页      面：153-158页

核心收录：

学科分类：07[理学] 0702[理学-物理学] 

主　　题：Dose calculation algorithm Collapsed cone algorithm Monte-Carlo algorithm 

摘      要：Treatment planning system calculations in inhomogeneous regions may present significant inaccuracies due to loss of electronic equilibrium. In this study, three different dose calculation algorithms, pencil beam (PB), collapsed cone (CC), and Monte-Carlo (MC), provided by our planning system were compared to assess their impact on the three-dimensional planning of lung and breast cases. A total of five breast and five lung cases were calculated by using the PB, CC, and MC algorithms. Planning treatment volume (PTV) and organs at risk (OARs) delineations were performed according to our institution s protocols on the Oncentra MasterPlan image registration module, on 0.3 - 0.5 cm computed tomography (CT) slices taken under normal respiration conditions. Intensity-modulated radiation therapy (IMRT) plans were calculated for the three algorithm for each patient. The plans were conducted on the Oncentra MasterPlan (PB and CC) and CMS Monaco (MC) treatment planning systems for 6 MV. The plans were compared in terms of the dose distribution in target, the OAR volumes, and the monitor units (MUs). Furthermore, absolute dosimetry was measured using a three-dimensional diode array detector (ArcCHECK) to evaluate the dose differences in a homogeneous phantom. Comparing the dose distributions planned by using the PB, CC, and MC algorithms, the PB algorithm provided adequate coverage of the PTV. The MUs calculated using the PB algorithm were less than those calculated by using. The MC algorithm showed the highest accuracy in terms of the absolute dosimetry. Differences were found when comparing the calculation algorithms. The PB algorithm estimated higher doses for the target than the CC and the MC algorithms. The PB algorithm actually overestimated the dose compared with those calculated by using the CC and the MC algorithms. The MC algorithm showed better accuracy than the other algorithms.