ESTRO 2025 - Abstract Book

S886

Clinical - Gynaecology

ESTRO 2025

Conclusion: Overall, the KD appears to be as tolerated as the standard diet during radiotherapy. The ongoing study is also designed to collect data on the impact of the KD on the oncological outcomes of patients.

Keywords: Gynaecological cancer, ketogenic diet

4456

Digital Poster Evaluating the incidence of sacral insufficiency fractures in gynecologic cancers treated with the VMAT technique. Andrea Grau 1 , Carlos García 1 , Reda Britel 2 , Carmen Gil 3 , Jon Gadea 1 , Francisco Jesús Mestre 1 , Gemma Valentina Llabrés 1 1 Radiation Oncology Department, Hospital Universitari Son Espases, Palma de Mallorca, Spain. 2 Hospital Radiology Departament (Osteomuscular pathology), Hospital Universitari Son Espases, Palma de Mallorca, Spain. 3 Hospital Radiophysics Departament, Hospital Universitari Son Espases, Palma de Mallorca, Spain Purpose/Objective: Sacral insufficiency fractures (SIF) are a significant and often underdiagnosed late complication following pelvic irradiation, contributing substantially to patient morbidity. Literature reports an overall SIF incidence of approximately 14%. Most of the studies on this topic have used 3D conformal radiotherapy (3DCRT). In contrast, the VMAT technique allows for highly conformal dose distributions, offering enhanced target volume coverage while better sparing normal tissues compared to 3DCRT. This study aims to evaluate the incidence of SIF in gynecological cancer patients treated with VMAT to determine whether the rate of occurrence is reduced. Material/Methods: A retrospective review was conducted on 97 patients diagnosed with gynecological cancer, all of whom received radiotherapy using the VMAT technique, either with curative or adjuvant intent. Pre-treatment imaging studies (CT, PET-CT and/or MRI) were compared with follow-up studies to identify the presence of SIF. Additionally, medical records were analyzed to correlate clinical observations with radiological findings.

Results: A total of 73 patients diagnosed with gynecological cancer and undergoing different intent of treatment were analyzed. The most employed radiotherapy regimen was 45 Gy at 1.8 Gy per fraction over 25 sessions (with 22 patients receiving a SIB to pelvic lymphadenopathies and 31 undergoing EBRT to the parametrium. The median