重离子束治癌中深度剂量分布优化

Optimization and Comparison of Depth-Dose Distribution of Heavy Ion Beam

针对兰州重离子研究装置所加速的120MeV/u ^(12)C离子束,利用模拟退火优化算法进行了Bragg峰展宽的剂量优化。取相同的展宽区域(30mm),4种不同的步长(2,1,0.5,0.25mm)进行Bragg峰展宽模拟。对所得到的剂量平均值,均方差,入射口剂量,峰坪比等优化结果的参数做了比较。讨论了重离子束治癌临床上最优的Bragg峰展宽模型的选取。

Heavy ion beams used for tumor therapy have some important advantages. Especially, the optimization of the depth-dose distribution of the heavy ion beam in a given focus of a tumor by using a Spread-Out Bragg Peak (SOBP) technique will greatly enhance the therapeutic effects for the tumor therapy. We adopted the simulated annealing algorithm to complete the optimization process for the high energy(- C 120MeV/u) heavy ion beam, which can be supplied by HIRFL, in a 30cm range of water and with 4 different step lengths to give a set of SOBP parameters such as the average dose, the input dose, the ratio of peak to plateau, the standard deviation, etc. The result shows that the selecting of 0.5-1mm as a step length is suitable.