一种基于生物准则的IMRT方案优化方法

Plan optimization method of IMRT based on biological criteria

针对调强放射治疗方案优化中,物理准则无法准确描述生物组织在非均匀剂量分布下的生物反应的问题,提出了基于生物准则的方案优化方法。首先根据病人各组织的剂量约束条件,建立基于生物准则的方案优化目标函数;然后采用L-BFGS-B算法求解方案优化问题。实验结果表明,在保证靶区剂量覆盖率的同时,相较于基于物理准则的方案优化方法,该方案优化后的危及器官并发症概率下降6.86%;相较于采用L-BFGS算法进行方案优化,该方案优化后的危及器官并发症概率下降1.30%。分析实验结果可得,将生物因子引入方案优化,能够更精确地反映组织的生物效应;采用L-BFGS-B算法能够快速、精确地求解方案优化问题。

Aiming at the problem that the physical indices cannot accurately describe the biological response, which is the bio-logical tissues under the non-uniform dose distribution for the plan optimization in the intensity modulated radiation therapy（IMRT）, this paper described a new, plan optimization method based on biological criteria. At first, the method established the objective function of the plan optimization based on biological criteria according to the dose constraints of various organiza-tions in the patient＇s. Then, it adopted the L-E〉FGS-E〉 algorithm to solve the optimization problem. Exthat, on the premise of guarantee the target dose coverage, compared with the plan optimization meterion,the proposed method reduced the NTCP by 6. 86%. Furthermore , the NTCP of the result opmethod decreased by 1.30% compared with the method for solving the optimization problem byThe results show that the introduct ion of the biological factors into the plan optimization can reflects the biological effects more accurately. And using the L-BFGS-B algorithm can solve the problems of the plan optimization more quickly and accurately.