摘要目的:探讨非小细胞肺癌患者光子调强适形放疗（IMRT）与质子调强适形放疗（IMPT）剂量分布的差异性。方法:回顾性分析2020年11月至2022年4月中国科学技术大学附属第一医院离子医学中心收治的8例行放疗的Ⅱ~Ⅲ期非小细胞肺癌患者的临床资料，对每例患者分别进行IMRT及IMPT计划设计，主要评价指标有靶区剂量分布参数[均匀性指数（HI）、适形度指数（CI）、靶区中95%及100%处方剂量曲线包绕体积的百分体积（V 95%和V 100%）]以及危及器官的平均剂量（D mean）和一定相对生物效应（RBE）剂量照射百分体积[患侧肺D mean、V 5 Gy（RBE）和V 20 Gy（RBE），双肺D mean、V 5 Gy（RBE）和V 20 Gy（RBE），心脏D mean、V 30 Gy（RBE）、V 40 Gy（RBE），脊髓最大剂量（D max），食管D mean]。 结果:与IMRT比较，IMPT可以降低双肺、患侧肺、脊髓、食管以及心脏的剂量参数水平，差异均有统计学意义（均 P<0.05），特别是双肺D mean[（4.1±1.8）Gy（RBE）比（6.9±1.9）Gy（RBE）]、V 5 Gy（RBE）[（15.9±7.1）%比（28.5±8.6）%]、V 20 Gy（RBE）[（7.4±3.5）%比（10.1±3.5）%]以及患侧肺D mean[（9.1±4.5）Gy（RBE）比（11.9±3.3）Gy（RBE）]均下降明显（均 P<0.001），但二者间靶区剂量分布参数水平差异均无统计学意义（均 P>0.05）。 结论:对于非小细胞肺癌患者，IMPT在双肺、患侧肺、脊髓、食管以及心脏的保护方面均优于IMRT。

abstractsObjective:To investigate the difference of dose distribution between intensity-modulated photon radiotherapy (IMRT) and intensity-modulated proton radiotherapy (IMPT) in patients with non-small cell lung cancer.Methods:The clinical data of 8 patients with stage Ⅱ-Ⅲ non-small cell lung cancer who received radiotherapy in Ion Medical center of the First Affiliated Hospital of University of Science and Technology of China from November 2020 to April 2022 were retrospectively analyzed. IMRT and IMPT radiotherapy plans were created for each patient separately, the main evaluation indicators were targeted area dose distribution parameters [homogeneity index (HI), conformity index (CI) and the percent volume of volume wrapped by 95% and 100% of prescription dose profile in the targeted area (V 95% and V 100%)], and the average dose (D mean) to the organ at risk and the percent volume of a certain relative biological effect (RBE) dose exposure [D mean, V 5 Gy(RBE) and V 20 Gy(RBE) of ipsilateral lung, D mean, V 5 Gy(RBE) and V 20 Gy(RBE) of bilateral lung, D mean, V 30 Gy(RBE) and V 40 Gy(RBE) of heart, maximum dose (D max) of spinal cord, and D mean of esophageal]. Results:In comparison with IMRT, IMPT reduced the levels of dose parameters in bilateral lung, ipsilateral lung, spinal cord, esophagus, and heart with statistically significant differences (all P < 0.05), especially in D mean of bilateral lung [(4.1±1.8) Gy (RBE) vs. (6.9±1.9) Gy (RBE)], V 5 Gy(RBE) [(15.9±7.1) % vs. (28.5±8.6)%], V 20 Gy(RBE) [(7.4±3.5)% vs. (10.1±3.5)%], and D mean of ipsilateral lung [(9.1±4.5) Gy (RBE) vs. (11.9±3.3) Gy (RBE)], all decreased significantly (all P < 0.001), but the differences in the levels of targeted area dose distribution parameters between them were not statistically significant (all P > 0.05). Conclusions:For patients with non-small cell lung cancer, IMPT is superior to IMRT in the protection of bilateral lung, ipsilateral lung, spinal cord, esophagus and heart.