食管癌腔内放射治疗技术的改进  

Technical improvement of brachytherapy for esophageal carcinoma

作　　者：肖泽芬[1] 苗延浚[1] 王亚非 冯宁远[1] 欧阳汉[2] 罗斗强[2] 

机构地区：[1]中国医学科学院中国协和医科大学肿瘤医院放射治疗科,北京100021 [2]中国医学科学院中国协和医科大学肿瘤医院,北京100021

出　　处：《中华放射肿瘤学杂志》2000年第1期29-32,F003,共5页Chinese Journal of Radiation Oncology

摘　　要：目的　改进食管癌腔内放射治疗的技术 ,探讨腔内放射治疗的适应证和剂量参考点的选择。方法　 18例食管癌采用改进后的气囊施源器在气囊充气状态、食管扩张情况下行MRI检查和腔内治疗。从MRI图像直接测出所需数据。结果　MRI检查能直观准确地显示肿瘤的大小及施源器在食管腔的整个行程。 83.3%的患者肿瘤最大浸润深度≤ 1.5cm。气囊施源器使源轴与食管粘膜的距离由 0 .30cm增加至 (0 .6 3± 0 .19)cm ;邻近病变段正常的食管粘膜的距离增加至(0 .89± 0 .14)cm ;气管膜状部的距离增加至 (0 .95± 0 .2 3)cm ,剂量由 2 0 31.0cGy分别下降至(90 5 .8± 2 0 5 .5 ) ,(6 0 1.3± 116 .8) ,(5 2 8.4± 16 7.8)cGy。设置参考点为 1.2 ,1.4cm时 ,超高剂量区均落在气囊以内 ,肿瘤最外缘 1.6cm处的剂量分别为 372 ,45 1cGy。肿瘤内的剂量分布范围分别在112 9～ 372 ,136 9～ 45 1cGy。结论　气囊施源器行MRI检查便于掌握肿瘤情况 ,利于适应证的选择 ;降低食管粘膜、气管膜状部的剂量使并发症降低。参考点设置的增大使肿瘤最大外缘的剂量提高 ,且肿瘤内的高。Objective To improve the technology of intraluminal brachytherapy for esophageal carcinoma, and to discuss its adaptability and the choice of dose reference point. Methods Eighteen patients with esophageal carcinoma,from Jan. 1997 to July 1998 , were examined by MRI and treated by brachytherapy under the state of airsac extending the esophagus by the improved balloon applicator. This set up was directly scanned by MRI.Results (1) MRI check was able to determine both the size of tumor and observe the whole applicator in the esophagus. Maximum depth of invasion of tumor, in 83.3% of patients, was equal to or less than 1.5?cm. (2)Balloon applicator was able to increase the average source mucosa distance from 0.30?cm to (0.63±0.19)?cm;The distance from the normal esophageal mucosa to the nearest tumor margin was increased to (0.89±0.14)?cm; the distance to the membranous portion of the trachea was increased to (0.95±0.23)?cm. The dose was lowered from 2031.0?cGy to (905.8±205.5),(601.3±116.8) and (528.4±167.8)?cGy. (3) With the reference point set 1.2?cm and 1.4 cm from the axis, the dose 1.6 cm from the outermost margin of the tumor was 372 and 451?cGy, with all the hot spots within the balloon. The dose distribution within the tumor ranged from 1129～372 and 1369～451?cGy.Conclusions (1) MRI carried out with the balloon application facilitates the understanding of the tumor condition and the choosing of technical adaptability so as to lower the dose on the esophageal mucosa and the membranous portion of the trachea. The complications of this treatment may be reduced. (2) The increase of distance to the reference point elevates the dose on the outer most margin of the tumor and reduces the differences between the high and low dose points within the tumor, making the dose distribution more even.

关 键 词：食管肿瘤 放射疗法 近距离放射疗法 

分 类 号：R735.1[医药卫生—肿瘤]