目的利用三维治疗计划系统分析自制有孔泡沫板在直肠癌术后常规放疗中对小肠和膀胱的保护作用。方法 9例直肠癌术后患者,俯卧于有孔泡沫板上常规模拟定位后,在俯卧位垫和不垫有孔泡沫板两种体位下分别进行CT扫描,CT扫描图像经局域网传输到治疗计划系统(Pinnacle3)进行三维重建,设计三野常规计划,通过剂量体积直方图比较两种体位下小肠和膀胱受照射的剂量和体积。结果使用有孔泡沫板时,小肠平均受照射剂量、10%~100%各等剂量曲线包绕的小肠体积、膀胱平均受照射剂量和30%~100%各等剂量曲线包绕的膀胱体积均显著减少,差异有统计学意义(P<0.05)。结论直肠癌术后常规放疗,应用自制有孔泡沫板可显著减少小肠和膀胱的受照射体积和剂量。 Objective To analyze the protective effect of self-made porous foam boards on the small intestine and bladder in patients undergoing conventional radiotherapy for rectal cancer using a three-dimensional treatment planning system. Methods Nine patients with postoperative rectal cancer underwent conventional simulated positioning on a perforated foam board. CT scans were performed under both the prone position pad and the non-padded foam board. The CT scan images were transmitted to the treatment plan via the local area network System (Pinnacle3) was reconstructed three-dimensionally to design the Sanno routine program to compare the dose and volume of irradiated small intestine and bladder at both positions using a dose-volume histogram. Results When the perforated foam board was used, the average small intestine volume of the small intestine, the volume of the small intestine surrounded by 10% ~ 100% of each dose curve, the average volume of the bladder and the volume of the bladder surrounded by each dose curve of 30% ~ 100% Significantly reduced, the difference was statistically significant (P <0.05). Conclusion Conventional radiotherapy of rectal cancer after operation, application of self-made porous foam board can significantly reduce the irradiated volume and dose of the small intestine and bladder.