剂量体积联合等效均匀剂量优化在肝癌调强放疗中的应用

Application of Dose Volume Combined with Equivalent Uniform Dose Optimization in Intensity Modulated Radiotherapy for Hepatocellular Carcinoma

目的:探讨剂量-体积(dose-volume,DV)联合等效均匀剂量(equivalent uniform dose,EllD)目标函数对肝癌调强放疗计划优化的影响。方法:随机选取20例原发性肝癌患者,对每例患者先做DV物理约束作为优化条件的计划,然后在保持物理约束条件不变的基础上,将危及器官增加最大EUD和靶区增加最小EUD的约束条件,重新优化计划。比较单纯使用DV目标函数优化计划和DV联合EUD目标函数优化计划对靶区和危及器官剂量学差异、结果:两组计划均能满足临床治疗要求。单纯DV优化和DV联合EUD优化(DV+EUD)的靶区剂量、CI和HI均无统计学差异(P>0.05);DV+EUD优化使正常肝的所受剂量较纯物理DV优化明显减小,同时肝、肾脏、胃、小肠等平均剂量也明显减低,差异具有统计学意义(P<0.05)。结论:DV+EUD优化应用到肝癌患者调强放射治疗中可以在满足靶区剂量临床要求的同时,更好地保护正常组织.

Objective: Objective: To investigate the effect of dose volume ( DV) combined with equivalent uniform dose (EUD) objective function on the optimization of intensity-modulated radiotherapy (IMRT) plan for hepatocellular carcinoma. Methods: Twenty patients with primary hepatocellular carcinoma were randomly selected, and DV constraints were first planned as optimization conditions for each patient. Then, on the basis of keeping the physical constraints unchanged, the maximum EUD was added to the organ at risk ( OAR) and the minimum EUD was added to the target area, and the plan was reoptimized. We then compared the difference between DV-based optimization and ( DV + EUD)-based optimization on target area and OAR. Results: Both the two groups of plans can meet the requirements of clinical treatment. The target dose, conformality index and heterogeneity indexwere not significant different between the two groups ( P > 0. 05 ). Compared to DVbased optimization,( DV + EUD)-based optimization significantly reduced the average dose tonormal liver, kidney, stomach and small intestine. The difference was statistically significant (P < 0. 05 ). Conclusion :( DV + EUD)-based optimization can better protect normal tissue and meet the clinical requirements of target dose in IMRT for liver cancer patients.