子宫颈癌放疗中盆腔剂量均匀分布的研究——提高宫颈癌疗效的新方法

HOMOGENEOUS DOSE DISTRIBUTION IN PELVIS RADIATION THERAPY OF CERVIX CARCINOMAM——NEW METHOD OF IMPROVING THERAPEUTIC EFFECT FOR CERVIX CARCINOMA

据1988年国际妇产联盟统计,Ⅱ、Ⅲ期宫颈癌放疗的五年生存率仍为50～70％及30～50％,其失败的主要原因之一是盆腔剂量分布不均匀。影响均匀分布的原因主要为子宫的偏移位或前后移位,这是长期以来未能解决的一大难题。本文介绍设计优化腔内放疗和楔形照射,达到盆腔由剂量均匀分布的目的。新的放疗方法应用于临床,降低了子宫旁组织及宫颈的复发率,提高了疗效。

Uneven pelvic dose distribution. owing to the extremely high incidence ofuterine deviation, remains one of the factors leading to the failure in intracavitaryradiotherapy for cervical cancer. In recent years. the application of high dose rateafterloading technique has randered favourable condition to correct the deviation ofapplicators. A simple way to correct the deviation of applicator is introduced in thispaper. In 50 cases studied. the dose difference between two sides of the pelvis couldbe reduced to minimum after cortecting the deviation of tandem and ovoid applica-tor In order to get homogeneops pelvic irradiation, the new external field withCentral Wedge Shield is designed. We have analyzed 217 cases of cervical cancer treated with new method of intra-cavitary and external irradiation. The recurrence rate of parametrium and cervixof uterus treated with new method is lower than that in conventional therapy. Theresults indicate that the new method of radiotherapy can improve the survival rate ofcervical cancer.