Technical aspects and perspectives of the vaginal mold applicator for brachytherapy of gynecologic malignancies

The importance of the quality of cervical cancer brachytherapy applicators has been reported, suggesting a direct influence of competent technical implant performance on outcome. In our institute, an original brachytherapy technique based on the use of a molded applicator for genital tract brachytherapy has been applied routinely in clinical practice. Here, we report the technical aspects of this customized applicator and perspectives on its use.

The first step consists of a vaginal impression that accurately shows the topography and extension of the tumor as well as the anatomy of the vagina and cervix. From this impression, an acrylic applicator is made. Then, the intended positions of the vaginal catheters are drawn on the surface of the mold by the radiation oncologist. Two plastic vaginal catheters are introduced and fixed on the internal surface of the molded applicator. A hole for the cervical os is made through which the uterine probe will be positioned.

This method allows for high specificity within the framework of a modern brachytherapy procedure, integrating the tumor topography, anatomy of the patient, and internal movements of target and critical volumes. This technique has been successfully extended to other tumor locations, such as genital tract rhabdomyosarcoma in children and postoperative endocavitary brachytherapy in patients with endometrial cancer.

Customization of a vaginal brachytherapy applicator allows for the maintenance of morphologic optimization throughout the treatment course, which better takes into account a fourth dimension: internal organ motion during the course of brachytherapy.