A dose-effect analysis of organs at risk during preoperative chemoradiotherapy for gastric cancer / 中华放射肿瘤学杂志

ABSTRACT

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 V3.5of ≤98.96% for the liver reduced LI, while a D2ccof ≤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.