ESTRO 2025 - Abstract Book

S793

Clinical - Gynaecology

ESTRO 2025

experiences [2-3] long-term outcomes were reported. These authors also reported other non-actuarial outcomes, like the systemic therapy free survival or median Progression Free Survival. Quality scores of the studies ranged from 6 to 13, indicating methodological variability. Conclusion: Even though the literature on MRI-Linac SBRT, specifically for gynecologic oligometastases, remains sparse, this review underscores MRI-Linac SBRT’s potential as an effective approach for treating oligometastatic gynecologic cancers, combining promising local control with reduced toxicity. As further evidence emerges, MRI-Linac SBRT may assume an increasingly pivotal role in the therapeutic landscape for oligometastatic disease in this setting. References: 1. Henke LE, Stanley JA, Robinson C, et al. Phase I Trial of Stereotactic MRI-Guided Online Adaptive Radiation Therapy (SMART) for the Treatment of Oligometastatic Ovarian Cancer. Int J Radiat Oncol Biol Phys. doi: 10.1016/j.ijrobp.2021.08.033. . 2. Cuccia F, Rigo M, Gurrera D, et al. Mitigation on bowel loops daily variations by 1.5-T MR-guided daily-adaptive SBRT for abdomino-pelvic lymph-nodal oligometastases. J Cancer Res Clin Oncol. 2021 Nov; doi: 10.1007/s00432 021-03739-8. . 3.Yavas G, Kuscu UE, Ayhan A, et al. The utility of 1.5 tesla MR-guided adaptive stereotactic body radiotherapy for recurrent ovarian tumor - Case reports and review of the literature. Int J Surg Case Rep. 2022 Oct;99:107696. doi: 10.1016/j.ijscr.2022.107696. Digital Poster Spatial analysis of ovarian transposition and its impact on radiation exposure during cervical cancer treatment Catarina Santana 1 , João Fonseca 1 , Lúcia Correia 2 , Maria Henriques 3 , Rafael Gonçalves 4 , Maria Fortunato 1 , Raul Colaço 1 , Nelson Ferreira 1 , Telmo Moedas 1 , Filomena Santos 1 1 Radiation Oncology, Portuguese Institute of Oncology, Lisbon, Portugal. 2 Obstetrics and Gynecology, Portuguese Institute of Oncology, Lisbon, Portugal. 3 Obstetrics and Gynecology, Maternidade Dr. Alfredo da Costa - ULS São José, Lisbon, Portugal. 4 Physics, Portuguese Institute of Oncology, Lisbon, Portugal Purpose/Objective: The purpose of this study was to analyze the relationship between the location of the transposed ovaries and the ovarian dose in cervical cancer patients who underwent surgery with ovarian transposition (OT) followed by adjuvant radiotherapy (RT). We aimed to evaluate the effectiveness of OT in preserving ovarian function and to predict the optimal position to achieve a satisfactory ovarian dose. Material/Methods: Patients with cervical cancer who underwent OT before pelvic RT between January 2020 and April 2024 were retrospectively analyzed. We evaluated the relationship between ovarian location and ovarian dosimetry. The optimal distance from the transposed ovary to the sacral promontory, iliac crest and planning target volume (PTV) margin was estimated using a receiver operating characteristic curve (ROC) analysis. Results: A total of 29 transposed ovaries from 15 patients treated with intensity-modulated radiation therapy (IMRT) were evaluated. The majority were located above the sacral promontory (58.6%, n = 17), below the iliac crest (51.7%, n = 15), and outside the PTV (86.2%, n = 25). The median distance from the center of the ovary to the sacral promontory Keywords: MRI-Linac; SBRT; Oligometastases 827