Localization of Point A in Cervical Cancer

Point A, the major critical point for dose specification of intracavitary brachytherapy, is defined as the crossing of uterine artery and ureter in treatment of cervical cancer. However, the currently advocated systems use hypothetical point A (HPA) to estimate the dosimetry of brachytherapy. This study is to localize anatomic point A (APA) of cervical cancer patients for reference of radiotherapy. We will use laparoscopic clipping technique to localize APA for cervical cancer patients during pelvic and paraaortic lymph node sampling. When these patients are receiving brachytherapy, orthogonal radiographs will be obtained after insertion of tandem and colpostats by using Henschke afterloading applicators.