膀胱容量变化对宫颈癌根治术后调强放疗中靶区照射剂量的影响

Effect of bladder volume change on radiation dose of target area in intensity-modulated radiotherapy after radical resection of cervical cancer

目的分析膀胱容量变化对宫颈癌根治术后调强放疗中靶区照射剂量的影响。方法选取我院收治的57例宫颈癌患者,所有患者均在宫颈癌根治术和盆腔淋巴结清扫后接受调强放疗。比较不同膀胱容量下靶区及危及器官(OAR)的体积及照射剂量,并分析不同膀胱容量下靶区各层面的位移变化情况。结果膀胱充盈时的膀胱体积明显大于排空时(P<0.05);膀胱充盈及排空时的CTV、PTV、直肠和小肠体积比较,差异均无统计学意义(P>0.05)。膀胱充盈时的小肠、膀胱照射剂量均明显低于膀胱排空时(P<0.05);膀胱充盈及排空时的CTV、PTV、直肠照射剂量比较,差异均无统计学意义(P>0.05)。不同膀胱容量下,宫底、宫颈口和质心在不同方位位移的改变均具有显著差异(P<0.05),其中头部方向位移的改变最大。结论在宫颈癌根治术后的调强放疗中,应充分考虑膀胱容量改变对靶区位移的影响,同时应尽量在膀胱充盈时进行调强放疗,以明显降低小肠、膀胱的照射剂量,提高放疗的安全性。

Objective To analyze the effect of bladder volume change on tradiation dose of target area in intensity-modulated radiotherapy after radical resection of cervical cancer.Methods A total of 57 patients with cervical cancer admitted in our hospital were selected,and all patients received intensity-modulated radiotherapy after radical resection of cervical cancer and pelvic lymph node dissection.The volume and radiation dose of target area and organ at risk(OAR)under different bladder volume were compared,and the displacement changes of all levels of target area under different bladder volume were analyzed.Results The bladder volume when the bladder was full was significantly greater than that when the bladder was empty(P<0.05),and there were no significant differences in the volume of CTV,PTV,rectum and small intestine when the bladder was full and empty(P>0.05).The radiation dose of small intestine and bladder when bladder was full were significantly lower than that when bladder was empty(P<0.05);and there were no significant differences in radiation dose of CTV,PTV and rectal between when bladder was full and empty(P>0.05).Under different bladder volumes,there were significant differences in the changes of the fundus,cervix and center of mass in different directions(P<0.05),and the most significant changes in the direction of the head.Conclusion In intensity-modulated radiotherapy after radical resection of cervical cancer,the impact of changes of bladder volume on the displacement of the target area should be fully considered.At the same time,intensity-modulated radiotherapy should be performed as far as possible when the bladder is full,so as to significantly reduce the radiation dose of the small intestine and bladder,and improve security of radiotherapy.