ESTRO 2025 - Abstract Book

S286

Brachytherapy - Gynaecology

ESTRO 2025

4631

Digital Poster 3D printed applicators in HDR interstitial and surface brachytherapy Daniel Hernandez Martinez 1 , Ana Carolina Ahumada 1 , Diego Arturo Ramirez 2 , Raul Eduardo Gonzalez Lopez 2 , Silvia Estela Haces 1 , Gabriel Ivan Hinojosa 1 , Karen Gonzalez Perez 1 , Abel Hernandez 1 , Oscar Vidal 3 1 Radiation Oncology, UANL, Monterrey, Mexico. 2 Innovacion Medicina, UANL, Monterrey, Mexico. 3 Obstetrics, UANL, Monterrey, Mexico Purpose/Objective: In interstitial and surface brachytherapy (BQT), 3D printing has enabled the development of customized devices that offer various advantages over traditional applicators. The availability of this technology allows for the precise design of applicators tailored to individual patient anatomies, leading to a better coverage of the treated area and improving dose distribution. There is no single material ideal for each situation. Each one of these has distinct physical properties, that allows the creation of different applicators and the ability to select the most suitable material for each clinical case. Material/Methods: Retrospective study devices for interstitial and surface BQT were developed. These were modeled using the program ‘Fusion 360’ to generate a 3D file, which was then printed on an Ender 3S1 Pro printer, utilizing Polylactic Acid (PLA) and Polyethylene Terephthalate Glycol-modified (PETG) as materials. For surface brachytherapy devices, a 3D slicer program was used to convert the patient’s surface into a 3D file (obtained from CT images), and silicone acetate mold was utilized as bolus for treatment. Results: A total of 19 patients were treated (Table 1) with diagnoses of cervical cancer (73.7%, 14), endometrial cancer (15.8%, 3), and skin cancer (10.5%, 2). Seventeen patients received interstitial BQT, while two underwent surface brachytherapy. Among the interstitial BQT patients, PLA was used for 14 devices (73.7%), while 3 devices (10.5%) were made from PETG. For the surface BQT, silicone acetate was used in 2 patients (10.5%). In all applications, proper insertion of interstitial needles was achieved, along with adequate dose conformity to the volume (Table 2). Various materials were analyzed to evaluate their usability and application in radiotherapy. To evaluate 3D-printed devices made from different materials and assess their advantages and disadvantages in interstitial and surface BQT