DeepPlan系统中快速直接子野优化在临床中的应用研究

目的 通过与Pinnacle计划系统在临床静态调强放疗（intensity modulated radiation therapy，IMRT）病例上的对比，研究自主研发的DeepPlan计划系统的快速直接子野优化模块的临床应用性能。方法 选取安徽省肿瘤医院25例肿瘤患者资料（其中6例头颈部、10例胸部和9例盆腔），分别使用DeepPlan和Pinnacle制定静态调强放疗计划，比较两个计划系统优化后的靶区适形度和均匀性、机器跳数、子野数的差异，并针对宫颈癌病例比较剂量学参数差异。结果 两个系统中所有病例均满足临床剂量要求，DeepPlan的平均优化时间为86 s，平均剂量计算时间为8.36 s。与Pinnacle相比，DeepPlan优化出的放疗计划具有更小的机器跳数、更多的子野和更大的靶区适形度指数（conformity index，CI），差异具有统计学意义（t=-3.208、2.912、2.875，P<0.05）；靶区均匀性指数（homogeneity index，HI）的差异无统计学意义（P>0.05）。在宫颈癌病例中，DeepPlan优化后的膀胱V₄₀低于Pinnacle （t=-5.498，P<0.05），小肠V₂₀高于Pinnacle （t=2.581，P<0.05）。结论 DeepPlan通过图形处理器（graphics processing unit，GPU）加速能够在较短时间内完成直接子野优化，得到满足临床要求的静态调强放疗计划。与Pinnacle相比，DeepPlan系统有更好的靶区适形度和更小的机器跳数，但子野数更多，对宫颈癌病例中膀胱的保护略好，对小肠的保护略差。

Study on the clinical application of the fast direct aperture optimization of DeepPlan treatment planning system

Objective To assess the clinical application of fast direct aperture optimization in self-developed DeepPlan treatment planning system, by comparing with the Pinnacle system in the clinical static IMRT cases. Methods Totally 25 clinical cases from Anhui Provincial Cancer Hospital were selected to get the static IMRT plan by DeepPlan and Pinnacle system, including 6 cases of head and neck cancer, 10 cases of chest and abdomen cancer and 9 cases of pelvis cancer. Then we compared the two groups of plans in terms of comformity and homogeneity, segment number and monitor unit. Finally, we compared the dosimetric parameters of cervical cancer cases in two systems. Results All of the cases in the two systems could satisfy the clinical dose requirements. The mean optimization time and the mean calculation time in DeepPlan were 86 s and 8.36 s, respectively. Compared with Pinnacle system, DeepPlan had less monitor unit, higher conformity index and higher number of apertures, with the significant statisical difference (t=-3.208, 2.912, 2.875, P<0.05). And there was no statistical difference in homogeneity index between DeepPlan and Pinnacle (P>0.05). For cervical cancer cases, the V₄₀ of bladder was significantly higher (t=-5.498, P<0.05) and the V₂₀ of small intestine was significantly lower (t=2.581, P<0.05) in DeepPlan system, compared to Pinnacle system. Conclusions With the graphics processing unit acceleration, the optimization method in DeepPlan system can produce efficient plans in a short time, which can satisfy the clinical requirement. Compared with Pinnacle system, the plan of DeepPlan system has better comfomity and less monitor units, but higher number of aperture. For cervical cancer, DeepPlan has more effective protection for bladder and less effective protection for small intestine.