重离子在生物组织中的阻止本领

根据中能重离子与靶物质相互作用的特点，将参数化的阻止本领计算方法进行了改进和推广，给出了计算重离子在人体组织及生物等效介质中阻止本领的方法。作为带电离子适形放疗的基础，计算了中能碳离子在肌肉、骨胳、脂肪、水及其他生物等效介质中的阻止本领，Bragg峰、射程等参量，并对计算方法的可靠性及在临床肿瘤治疗剂量控制方面的应用进行了分析。参数化的计算方法能满足实际应用的要求。

Stopping Power of Heavy Ions in Human Body Tissue

In charged particle conformal radiotherapy, the energy deposition in the tumour area of the heavy ion beam is controlled by the energy range, energy straggling and the Bragg peak. A parameterized formula is developed to calculate stopping power values for heavy ions, such as ^12C in human tissue and tissue equivalent materials with the uncertainty about 3 %. The ranges and stopping powers for ^12C in bone, fat, muscle, water and tissue equivalent materials, polyethylene, lucite and polystyrene, are cal- culated. The energy-range relation in the muscle for ^12C is obtained. The energy straggling and angular straggling for ^12C in the muscle increase when the energy loss increases. The conformity of the energy deposition in the cancer therapy is discussed.