A Complete Set of Rotatable Applicator System for Intensity Modulated Brachytherapy of Advanced Cervical Cancers

Abstract

To develop a complete set of rotatable applicator system for intensity modulated brachytherapy (IMBT) of advanced cervical cancers, and to install them in a brachytherapy treatment room. Recently, we developed a novel tandem applicator with a rotatable internal shield for IMBT. However, a complete set of applicator system is required to treat a patient with advanced cervical tumor, which consists of IMBT tandem applicator, coupling structure between IMBT tandem and conventional ovoids, their leveling device, rotation system of IMBT tandem (including mini DC-motor, motor adaptor, motor controller, and interfacing software), mechanical channel conversion adaptor, semi-automatic beam delivery system, dummy IMBT tandem, applicator clamping device, QA system of IMBT tandem, Pelvic immobilizer etc. In addition, a safe and reliable treatment workflow and protocol should be established. Most of the listed instruments has been developed, and their performance was tested for IMBT. Especially, the QA system of IMBT tandem could check dosimetrically the coincidence between reading and real angles on daily base. The semi-automatic beam delivery system was also tested safely by using a check cable instead of Ir-192 source. We confirmed that the check cable could be loaded into the IMBT tandem sequentially after rotating the shield to a required angle for treatment. All of the developed instruments were installed after the performance test (Table 1), and a treatment workflow was designed on the basis of current workflow. We developed a complete set of rotatable applicator system for IMBT of advanced cervical cancers, and installed them in our brachytherapy treatment room after their successful performance test. The entire system will be tested comprehensively soon.Abstract 1264; Table 1A complete set of rotatable applicator system for IMBT of advanced cervical cancers is listed below except for an inverse treatment planning system.No.Items for IMBTDevelopmentInstallation1IMBT tandem applicator with rotatable tungsten shield○○2Coupling structure between IMBT tandem and conventional ovoids, and their leveling device○○3Rotation system of IMBT tandem including mini DC-motor, motor adaptor, motor controller, and interfacing software○○4Mechanical channel conversion adaptor○○5Semi-automatic beam delivery system○under6Dummy IMBT tandem○○7Applicator clamping device○○8QA system of IMBT tandem○○9Pelvic immobilizerunderunderAbbreviations: IMBT = intensity modulated brachytherapy.○ Means the development/installation has already been done. Open table in a new tab