摘要
目的:研究宫颈癌近距离腔内照射时直肠、膀胱的在线剂量,同时寻求减少直肠、膀胱剂量的方法。方法:随机选取10例宫颈癌患者分成两组,分别使用在阴道施源器顶端加了3mm铅皮和没加铅皮的施源器进行CT扫描后,通过网络将患者影像传入治疗计划系统,按A点600cGy的处方制定治疗计划,同时计算出直肠膀胱的剂量,然后将在60Coγ线辐射场内校准过的IBF-5和IDF-THIN在进行宫颈癌近距离腔内照射时,插入患者的直肠、膀胱位置进行监测,得出测量点的剂量,并与计划系统中该点的剂量进行比对。结果:结果显示对于膀胱两组测得的剂量非常相似,但与计划剂量相差比较大,这是因为在治疗时电离室位置发生改变;对于直肠,两组测量结果相差较大,未加铅皮的结果跟计划结果相近,而加了铅皮的测量结果明显减小。结论:通过测量我们知道在宫颈癌腔内照射中我们要对每个患者制定个体化治疗计划并实施在线的剂量监测,同时在测量中要特别注意操作技巧。
Objective： Research on the in vivo dose of rectum and bladder in intracavitary brachytherapy of cervix cancer and methods of reducing the dose of these organs. Methods： The IBF-5,1DF-THIN semi-conductor ionization chamber calibrated in ^60Coγ radiation field, were used. 10 cases of cervix cancer,divided into two groups,were chosen randomly in the experiment. Two type of applicator were used respectively. For one of them,we added 3mm Pb block on the top of applicator, for the other ease was without the applicator. The applicators were put in patient＇s body before CT scanning. The image was transmitted to PLATO planning system through local network, the treatment plan was made and the 600 cGy prescription dose was given for A point, the rectum and bladder dose were calculated. Then the intracavitary brachytherapy was carried out and the in vivo dose of rectum and bladder was made. The measured dose was compared to the planning dose,and the result was analyzed. Results： For bladder,the measured dose of two groups were similar essentially,but it shows a disagreement between measured dose and planning dose,due to the position of chamber was changed during the treatment. For rectum,we can find that there are significant difference between two group measured dose,the measured dose of the group with general applicator is similar to the planning dose basically,but the measured dose of other group,the rectum dose was reduced significantly, because the Pb block has obviously offset on the rectum dose. Conclusion： Through in vivo measurement, individual treatment planning and in vivo dose verification should be done for every case in intracavitary brachytherapy of cervix cancer and much technology attention must be paid during in vivo verification.
出处
《中国医学物理学杂志》
CSCD
2007年第4期243-244,242,共3页
Chinese Journal of Medical Physics
关键词
宫颈癌
近距离治疗
半导体电离室
cervical cancer
brachytherapy
semi-conductor dosimeter
