手术与非手术妇科恶性肿瘤患者适形调强放疗中危及器官运动的比较

Comparison of organ at risk motion during conformal intensity-modulated radiotherapy in patients with surgical and non-surgical gynecologic malignant tumor

目的探讨手术与非手术妇科恶性肿瘤患者在调强放疗(IMRT)中危及器官的体积和位置变化。方法纳入该院2021年1-3月收治的31例行盆腔IMRT的妇科恶性肿瘤患者,根据是否手术将患者分为手术组(n=15)和未手术组(n=16)。在放疗的第10、15、20次行CT校位扫描,勾画3次校位CT图像上的小肠、膀胱、直肠,并将其融合在放疗前的定位CT图像上,比较两组危及器官在放疗过程中的体积、体积变化率、体积重复率和中心点位移差异。结果两组膀胱和直肠的体积、体积变化率、体积重复率比较,差异均无统计学意义(P>0.05)。两组小肠的体积变化率无明显差异(P>0.05),但手术组小肠的体积重复率明显高于未手术组(P=0.001)。手术组的直肠在头脚方向位移较未手术组大,差异有统计学意义(P=0.018)。结论妇科恶性肿瘤术后患者的小肠运动较未手术者减弱,而直肠运动在头脚方向较大,放射肿瘤科医师需分别考虑手术和未手术患者小肠和直肠运动特点,以设计合理的靶区减少相关不良反应。

Objective To investigate the volume and location changes of organ at risk during intensity-modulated radiotherapy(IMRT)in the patients with and without surgery for gynecologic malignant tumor.Methods Thirty-one patients with gynecologic malignant tumors undergoing pelvic IMRT in this hospital from January to March 2021 were included and divided into the operation group(n=15)and the non-operation group(n=16)according to whether or not underwent operation.The CT calibration scans were performed on the 10th,15th and 20th times of radiotherapy,and the small intestine,bladder and rectum were outlined on the three times of calibration CT images,which were fused on the positioning CT image before radiotherapy.The volume,volume change rate,volume repetition rate and centroid displacement during radiotherapy were compared between the organs at risk of the two groups.Results There was no statistically significant difference in the volume,volume change rate and volume repetition rate of bladder and rectum between the two groups(P>0.05).There was no statistically significant difference in the volume change rate of small intestine between the two groups(P>0.05),but the volume repetition rate of small intestine in the operation group was significantly higher than that in the non-operation group(P=0.001).The displacement of rectum in the head and foot direction in the surgical group was larger than that in the non-surgical group,and the difference was statistically significant(P=0.018).Conclusion The small intestine motion is weakened in postoperative patients with gynecologic malignant tumor compared with those without surgery,while the rectum motion is larger in the head and foot direction.The radiation oncologists need to consider the characteristics of small intestine and rectum motion in patients with and without surgery separately to design the reasonable target areas for reducing the related adverse effects.