宫颈癌腔内联合组织间插植治疗与三管式腔内后装治疗的剂量学比较

Dosimetric comparison between intracavitary/intesrstitial brachytherapy and three-tubed brachytherapy in cervical cancer

目的:比较腔内联合组织间插植治疗与三管式腔内后装治疗在宫颈癌后装近距离中的剂量学差异。方法:回顾性分析我院2017年2月至2017年12月后装治疗宫颈癌患者40例,FIGO分期为Ⅰb-Ⅳa期。其中20例患者采用核通Fletch三通道施源器进行三管式后装腔内治疗(ICBT),20例患者采用核通Fletch宫腔管联合4针插植进行治疗(IC/ISBT)。在靶区D 90尽量接近600 cGy条件下,评估单次后装治疗靶区适形指数(COIN)、均匀指数(HI)、膀胱及直肠的剂量学差异。结果:IC/ISBT组患者的高危CTV靶区COIN明显高于ICBT组(P=0.000),而HI指数两组患者并无差异(P=0.917)。IC/ISBT组患者膀胱D 1 cm 3和D 2 cm 3剂量明显低于ICBT组( P =0.015, P =0.023)。IC/ISBT组患者直肠D 1 cm 3 剂量明显低于ICBT组( P =0.040),D 2 cm 3 剂量也较ICBT组低( P =0.070),但差异无统计学意义。两组患者总治疗时间差异无统计学意义( P =0.500)。 结论: 腔内联合4针插植治疗较三管式腔内放疗可以显著提高COIN而不改变靶区高剂量区范围和总治疗时间,并降低危及器官膀胱、直肠的受量。

Objective:To explore the dosimetric advantage of intracavitary/interstitial brachytherapy(IC/ISBT)in after-loading brachytherapy through comparing IC/ISBT and three-tubed brachytherapy(ICBT).Methods:40 patients suffering cervical cancer with FIGO stageⅠb-Ⅳa were retrospectivly analyzed from February to December in our hospital.20 patients received ICBT,and another 20 patients received IC/ISBT undergoing 4 needles.The conformal index(COIN),homogeneity index(HI)and dosimetric differences of D 2 cm 3 in bladder and rectum were evaluated on grounds of dosage of targets reached 600 cGy for D 90.Results:The COIN of IC/ISBT was significantly higher than ICBT(P=0.000).However,HI in two groups had no difference.The doses of D 1 cm 3 and D 2 cm 3 of bladder were significantly lower in IC/ISBT than ICBT(P=0.015,P=0.023).For rectum,the dose of D 1 cm 3 was significantly lower in IC/ISBT than ICBT(P=0.040),and dose of D 2 cm 3 was also lower in IC/ISBT than ICBT but haven't reached statistically significance(P=0.070).The statistically significance of treatment overall time did not exist between two groups(P=0.500).Conclusion:The group of IC/ISBT could not only improve COIN but increasingly reduce irradiation dose in rectum and bladder,otherwise,would not change the high dose regions of CTV.