High dose-rate intracavitary brachytherapy for cervical carcinomas with lower vaginal infiltration

This report presents the clinical applications of an automated treatment-planning program of high-dose-rate intracavitary brachytherapy (HDR-ICBT) for advanced uterine cervical cancer infiltrating the parametrium and the lower vagina.

We adopted HDR-ICBT under optimized dose distribution for 22 cervical cancer patients with tumor infiltration of the lower half of the vagina. All patients had squamous cell carcinoma with International Federation of Gynecology and Obstetrics clinical stages IIB-IVA. After whole pelvic external beam irradiation with a median dose of 30.6 Gy, a conventional ICBT was applied as "pear-shaped" isodose curve. Then 3-4 more sessions per week of this new method of ICBT were performed. With a simple determination of the treatment volume, the cervix-parametrium, and the lower vagina were covered automatically and simultaneously by this program, that was designated as "utero-vaginal brachytherapy". The mean follow-up period was 87.4 months (range, 51.8-147.9 months).

Isodose curve for this program was "galaxy-shaped". Five-year local-progression-free survival and overall survival rates were 90.7% and 81.8%, respectively. Among those patients with late complications higher than Grade 2 Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer morbidity score, only one (4.5%) developed severe proctitis.

Because of the favorable treatment outcomes, this treatment-planning program with a simplified target-volume based dosimetry was proposed for cervical cancer with lower vaginal infiltration.