胃癌术前放化疗正常组织放射损伤的剂量效应分析

A dose-effect analysis of organs at risk during preoperative chemoradiotherapy for gastric cancer

分析影响胃癌术前放化疗正常组织损伤的临床和剂量体积因素,为优化3DRT计划提供参考。方法 分析 58例完成新辅助治疗的局部进展期胃腺癌术前放化疗联合手术及辅助化疗或术前化疗联合手术及辅助化疗的患者。术前化疗组（28例）：术前xelox （卡培他滨＋奥沙利铂）方案 2~3程,术后xelox方案 3~4程（共6程）。术前放化疗组（30例）：首程xelox化疗后第 14—21天内开始3DRT （45 Gy分25次）,同期2程xelox化疗,术后xelox方案3程。结合治疗中相关实验室指标和临床症状,开展正常组织损伤的临床和剂量体积因素分析。结果 患者术前肝脏、肾脏和十二指肠损伤发生率分别为22%、48%和33%;治疗结束后肝脏和肾脏损伤发生率分别为35%和49%。所有肝、十二指肠损伤经对症处理后均不影响治疗,肾损伤不需特殊处理可恢复正常。分析提示术前放化疗较术前化疗增加肝损伤发生率（P=0.00、0.03）,而肾损伤仅与放疗前肾小球滤过率相关（P=0.80、0.13）。肝V3.5≤98.96%,十二指 肠D2 cm^3≤48 Gy。结论 胃癌术前放化疗方案是安全的。术前放化疗较术前化疗未增加肾损伤风险,但有加重肝损伤趋势,值得重视和改进。

Objective To investigate the clinical and dose-volume factors for damages to organs at risk （OARs） during preoperative chemoradiotherapy for gastric cancer, and to provide a reference for optimization of radiotherapy plans to avoid or reduce damages to OARs. Methods A total of 58 patients with locally advanced gastric adenocarcinoma undergoing neoadjuvant treatment were enrolled as subjects. In those patients, 30 received preoperative chemoradiotherapy combined with surgery and adjuvant chemotherapy, while others received preoperative chemotherapy combined with surgery and adjuvant chemotherapy. The preoperative chemotherapy group received 2-3 cycles of xeloxregimen （capecitabine＋oxaliplatin） before surgery and 3-4 cycles of xeloxregimen after surgery （a total of 6 cycles）. The preoperative chemoradiotherapy group received preoperative radiotherapy （45 Gy in 25 fractions） combined with 2 cycles of concurrent xeloxchemotherapy at 14-21 days after the first cycle of xeloxregimen, as well as 3 cycles of xeloxchemotherapy after surgery. The analyses of clinical and dose-volume factors for damages to OARs were performed based on laboratory indices and clinical symptoms during the treatment. Results In all the patients, the incidence rates of liver injury （LI）, renal injury （RI）, and duodenum injury （DI） before surgery were 22%,48%, and 33%, respectively;the incidence rates of LI and RI after treatment were 35% and 49%, respectively. After appropriate treatment, neither LI nor DI affected the treatment of gastric cancer. RI healed without any special treatment. Compared with preoperative chemotherapy, preoperative chemoradiotherapy caused higher incidence of LI （P=0.00,0.03）.RI was only associated with glomerular filtration rate before radiotherapy （P=0.08,0.13）. A V3.5 of ≤98.96% for the liver reduced LI, while a D2cc of ≤48 Gy for the duodenum reduced DI. Conclusions Preoperative chemoradiotherapy is safe for treating gastric cancer. Compared with preoperative chemotherapy, preoperative chemoradiotherapy does not increase the risk of RI. However,preoperative chemoradiotherapy tends to increase LI.Further studies are needed to improve the treatment method.