OPTIMIZING BRACHYTHERAPY FOR LOCALLY ADVANCED CERVICAL-CANCER

Purpose: No adequate high dose rate brachytherapy technique exists to cover all known tumor volume by using one type of applicator in patients presenting,vith a cervix carcinoma extending to the vaginal wall and the parametria. Methods and Materials: We adapted the existing high dose rate applicator, existing of two ovoids and one intrauterine tube, to achieve adequate irradiation of the uterus, the parametria, and the vaginal wall in these patients. Using the optimization program of the Nucletron Planning System, isodose curves were obtained to apply a specified dose of 8.5 Gy at point A and at 5 mm depth of the vaginal wall by using a single applicator for both fractions. Results: Fractionated high dose rate brachytherapy can be given with both higher dosimetric accuracy and more adequate irradiation of the vaginal and the parametrial tumor component after adapting the existing high dose rate applicator for brachytherapy in cervical cancer.