Comparative Dosimetric Study using Various Applicators for Vaginal Cuff Brachytherapy; Three Ovoid Technique Proposal |Biomedgrid

Purpose: Vaginal-cuff brachytherapy is the adjuvant treatment in women with intermediate-high risk of endometrial or uterine cervical cancers. The most common applicators are single-channel vaginal cylinders and two-symmetric ovoid applicators according to the shape of the stump. For two-ovoid applicators, the distance between them depends on the therapist and vaginal size. A greater distance means a lower dose in the vaginal apex point. To overcome this problem, this study proposes brachytherapy plans using three-ovoid applicators to improve insufficient dose distribution. Materials and Methods: Clinical dosimetry was calculated using HDRPlus software, and patients were treated using the BEBIG MultiSource® High Dose Rate brachytherapy treatment unit with a cobalt-60 source. In this study, three types of applicators (cylinder, two-ovoid, and three-ovoid) and three brachytherapy plans were compared for optimal dose delivery. The three-ovoid applicators used were two-ovoids and tandem with multiple holding discs. To compare the three brachytherapy plans, the prescription point, vaginal apex point, bladder, and rectal dose were evaluated.