Shahmohammadi Beni Mehrdad, Ng C Y P, Krstic D, Nikezic D, Yu K N
Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong.
Faculty of Science, University of Kragujevac, Serbia.
PLoS One. 2017 Mar 31;12(3):e0174836. doi: 10.1371/journal.pone.0174836. eCollection 2017.
Radiotherapy is a common cancer treatment module, where a certain amount of dose will be delivered to the targeted organ. This is achieved usually by photons generated by linear accelerator units. However, radiation scattering within the patient's body and the surrounding environment will lead to dose dispersion to healthy tissues which are not targets of the primary radiation. Determination of the dispersed dose would be important for assessing the risk and biological consequences in different organs or tissues. In the present work, the concept of conversion coefficient (F) of the dispersed dose was developed, in which F = (Dd/Dt), where Dd was the dispersed dose in a non-targeted tissue and Dt is the absorbed dose in the targeted tissue. To quantify Dd and Dt, a comprehensive model was developed using the Monte Carlo N-Particle (MCNP) package to simulate the linear accelerator head, the human phantom, the treatment couch and the radiotherapy treatment room. The present work also demonstrated the feasibility and power of parallel computing through the use of the Message Passing Interface (MPI) version of MCNP5.
放射治疗是一种常见的癌症治疗方式，会向目标器官输送一定剂量的辐射。这通常通过直线加速器产生的光子来实现。然而，患者体内及周围环境中的辐射散射会导致剂量分散到非主要辐射目标的健康组织中。确定分散剂量对于评估不同器官或组织中的风险和生物学后果至关重要。在本研究中，提出了分散剂量转换系数（F）的概念，其中F = （Dd/Dt），Dd是非目标组织中的分散剂量，Dt是目标组织中的吸收剂量。为了量化Dd和Dt，使用蒙特卡罗N粒子（MCNP）软件包开发了一个综合模型来模拟直线加速器机头、人体模型、治疗床和放射治疗室。本研究还通过使用MCNP5的消息传递接口（MPI）版本展示了并行计算的可行性和能力。
