Intracavitary vaginal brachytherapy using a custom balloon applicator

A custom balloon applicator was created to deliver intracavitary high-dose-rate brachytherapy to a patient with a superficial vaginal cancer. The patient was unable to be treated conventionally due to an extremely narrow introitus that prevented the introduction of a conventional cylinder applicator. The custom applicator was constructed by inserting a straight titanium tandem applicator through the drainage lumen of a Foley catheter. The applicator was inserted and the catheter balloon was inflated when positioned at the vaginal apex. Three brachytherapy treatments were performed using this technique. Individual balloon eccentricities resulted in small radial tandem offsets within the balloon. This phenomenon was exploited by orientating the tandem offset in the direction of the target volume. Acceptable dosimetry was achieved for all fractions and the procedure was very well tolerated. The custom applicator was a viable solution that was safely developed in a short time frame using equipment readily available in our department.