DESIGN OF 3D-PRINTED MULTI-CATHETER GYNECOLOGICAL BRACHYTHERAPY APPLICATORS WITH CUSTOMIZABLE CATHETER POSITIONS

Abstract

Brachytherapy patients with asymmetric gynecological targets are often planned with vendor-supplied applicators and templates, known as the Miami or MUPIT applicator. This research designed multi-catheter applicators with patient-specific catheter positions, which could be created using a 3D printer. In this retrospective REB approved study, twenty-five past patients who received vaginal brachytherapy at the QEII Cancer Centre were chosen. The catheters were reconstructed according to the patient’s anatomy. DVH parameters were compared for the patient-specific applicator and original applicator treatment plans. The high dose regions for all plans showed a decrease for the patient-specific with V200 decreasing from 7.4% to 3.3% (p<0.0001), for an intracavitary applicator. For the interstitial plans, V150 decreased from 38.6% to 34.0% (p<0.0006) for the patient-specific applicators. The quality indices were statistically better for the patient-specific plans. When comparing applicator design, a patient-specific, applicator resulted in better coverage of the CTV, with improved sparing of the OARs.