中文摘要：

目的 探讨CT引导下腔内联合组织间插植3D-IGBT局部晚期宫颈癌的剂量学优势.方法 分析2013-2014年于本院接受根治性外照射及腔内联合组织间插植3D-IGBT的局部晚期宫颈癌患者45例,FIGO分期（2009年）为ⅠB2-ⅣA期.同一患者行腔内联合组织间插植^192Ir治疗后,在原影像上去掉插植针作用,仅使用腔内施源器制定治疗计划.比较前后两组计划中高危CTV的D90％、中危CTV的D90％和膀胱、直肠、乙状结肠、小肠的D2cm^3剂量学差异,并行配对t检验.结果 共制定260次后装治疗计划,其中腔内联合组织间插植治疗计划130例、腔内治疗计划130例.腔内联合组织间插植治疗较腔内治疗高危CTV的D90％、中危CTV的D90％显著增高（P=0.000、0.000）,膀胱、直肠的D2cm3显著降低（P =0.000、0.006）.结论 局部晚期宫颈癌使用腔内联合组织间插植3D-IGBT在获得更高靶区剂量的同时降低了膀胱、直肠受量.

英文摘要：

Objective To explore the dosimetric advantages of computed tomography-based and ultrasound-guided three-dimensional image-quided brachytherapy （3D-IGBT） combined with intracavitary/interstitial （IC/IS） brachytherapy for locally advanced cervical cancer.Methods A total of 45 patients with FIGO （2009） stage ⅠB2-ⅣA locally advanced cervical cancer who received radical external beam radiotherapy and 3D-IGBT combined with IC/IS brachytherapy in our hospital from 2013 to 2014 were analyzed.After the treatment with ^192Ir-based IC/IS brachytherapy,patients had needles removed from the original images and received treatment only from IC radiation sources.Dosimetric differences in the planning D90 for high-risk clinical target volume （HR-CTV）,D90 for intermediate-risk CTV （IR-CTV）,and D2 cm3 for the bladder,rectum,sigmoid colon,and small intestines were determined and analyzed by paired t-test.Results A total of 260 after-loading treatment plans,including IC/IS treatment plans for 130 patients and IC treatment plans for 130 patients,were made.The D90 for HR-CTV and D90 for IR-CTV in the IC/IS brachytherapy group were significantly higher than those in the IC brachytherapy group （P =0.000;P =0.000）.Moreover,the average D2cm^3 values for the bladder and rectum were significantly reduced in the IC/IS brachytherapy group compared with those in the IC brachytherapy group （P =0.000;P =0.006）.Conclusions The 3D-IGBT combined with IC/IS brachytherapy not only achieves a higher dose for the target volume,but also reduces the radiation dose to the bladder and rectum in the treatment of locally advanced cervical cancer.