乌德勒支施源器在宫颈癌3D—IGBT应用观察

The clinical application research of Utrecht applicator in three-dimensional image guided brachytherapy （3D-IGBT） for cervical cancer

目的观察乌德勒支施源器在局部晚期宫颈癌3D—IGBT中的临床应用情况，揭示其在IC—IS的应用规律。方法回顾分析45例接受根治性放疗的局部晚期宫颈癌患者．外照射后行3D．IGBT，其中45例130次IC—IS入组。将满足计划目标剂量分次定义为A组（37例86人次）。余为B组（22例44人次），成组t检验差异。结果施源器使用15、20、25mm卵圆体的频率分别为50．0％、20．0％、30．0％，30mm型号无使用。共置插植针499根，6、7、10、11孔位使用频率分别为23．1％、21．2％、21．2％、24．1％。A组平均插植针数为3．7根明显少于B组4．2根（P=0．008）。A组的HR-CTV平均体积为（40．71±18．43）cm3小于B组（51．81±14．74）cm3（P=0．001），A组HR．CTV的宽和高小于B组（P=0．011、0．006）；而厚相似（P=0．595）。高与插植深度的差两组相似（P=0．366），宽与左右针孔间距的差A组小于B组（P=0．007）。结论局部晚期宫颈癌行IC—IS时．乌德勒支施源器的卵圆体多选用25mm及以下型号，插植孔位多选用6、7、10、11号。在插植针数≥4根、深度≥3cm时，宽度是影响计划剂量的主要因素。

Objective To investigate the clinical application of Utrecht applicator in threedimensional image-guided brachytherapy （3D-IGBT） for locally advanced cervical cancer, as well as its application discipline in intracavitary/interstitial （IC/IS） therapy. Methods A retrospective analysis was performed for the clinical data of 45 patients with locally advanced cervical cancer who received radical radiotherapy, and the patients received external beam radiotherapy followed by 3D-IGBT. A total of 130 times （n = 45） of IC/IS therapy were performed, and the patients who received such therapy were all enrolled. The patients who met the target dose fractionation defined in the plan were enrolled as group A （ n= 37, 86 times）,and the other patients were enrolled as group B （n= 22,44 times）. Two groups difference was analyzed with Group t-test. Results The frequencies of use of 15-,20-, and 25-mm ovoids by the applicator were 50.0%,20. 0%, and 30. 0%, respectively, and the 30-mm ovoid was not used. A total of 499 needles were used,and the frequencies of use of 6,7, 10, and 11 insertion holes were 23. 1%,21.2%,21.2%,and 24. 1% ,respectively. Group A had a significantly lower mean number of the needles than group B （3.7 vs. 4. 2,P=0. 008）. Compared with group B, group A had a significantly lower mean high-risk clinical target volume （CTV） （ 40.71 ± 18.43 em3 vs. 51.81 ± 14. 74 cm3, P = 0. 001 ）, as well significantly lower width and height of high-risk CTV （P = 0. 011 and 0. 006）, but the thickness of high-risk CTV was similar between the two groups （P= 0. 595）. The difference between height and insertion depth （DH） was similar between the two groups （P= 0. 366）. Group A had a smaller difference between width and pinhole distance DW than group B （P= 0. 007）. Conclusions When IC/IS therapy is performed for locally advanced cervical cancer, the 15-,20-, and 25-mm ovoids of Utrecht applicator and 6,7,10, and 11 insertion holes are frequently used. When the number of needles is no less than 4 and the depth is no less than 3 cm, width is the major factor which affects the planned dose.