ESTRO 2025 - Abstract Book

S859

Clinical - Gynaecology

ESTRO 2025

Keywords: Radiotherapy, Acute Toxicity, Risk factor

References: 1)

Ramlov A, Assenholt MS, Jensen MF, Grønborg C, Nout R, Alber M, Fokdal L, Tanderup K, Lindegaard JC. Clinical implementation of coverage probability planning for nodal boosting in locally advanced cervical cancer. Radiother Oncol. 2017 Apr;123(1):158-163.

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Digital Poster First institutional report from Argentina on stereotactic body radiotherapy (SBRT) in patients with oligometastatic gynecologic cancer Gustavo Ferraris, Ariel Gomez Palacios, Mariano Salum, Diego Fernandez, Lucas Caussa, Ofelia Perez Conci, Belen Raiden, Luciana Brun, Maria Fernanda Diaz Vazquez Radioterapia, Centro de Radioterapia Dean Funes, Cordoba, Argentina Purpose/Objective: Evidence supporting the use of SBRT in patients with oligometastatic disease is growing; however, few studies specifically address the role of SBRT in patients with oligometastatic gynecologic cancer.(1-4) Objectives: To assess local control and its impact on overall survival (OS) in patients with oligometastatic gynecologic cancer. Material/Methods: This is a retrospective study involving patients with oligometastatic endometrial and uterine gynecologic cancers treated with SBRT between 2017 and 2023. Clinical and radiological data were collected to evaluate overall survival (OS), metastasis-free survival (MFS), local control (LC), and toxicities. Lesion response was evaluated using RECIST criteria, and Kaplan-Meier analysis was used to assess OS, MFS, and LC. Results: A total of 30 patients with 43 metastatic lesions were included, with a mean follow-up of 32 months. The median age was 57 years. According to the origin of the primary tumor, 55% were endometrial neoplasms, and 45% were cervical. The most frequently irradiated sites were lymph nodes (55%), lung (23%), pelvis (13%), and bone (9%). SBRT dose regimens were 25-50 Gy in 3-5 fractions, with a mean administered BED of 70 Gy (range 37.5 Gy-151.2 Gy). At follow-up, all patients were alive one year post-treatment, with 60% alive at three years. Mean OS was 40.6 months, MFS was 22.3 months, and three-year LC was 95%. The median interval of systemic treatment-free survival after SBRT was 24 months. Acute G1-2 toxicities occurred in 15% of patients (including fatigue and gastrointestinal toxicities), with no instances of acute G3-4 toxicity. Conclusion: The results suggest that SBRT may be an effective and safe option for treating patients with oligometastatic gynecologic cancer. We observed adequate local control as well as a delay in the need for systemic treatment, consistent with international studies.

Keywords: gynecological cancer, SBRT, oligometastasis

References: 1-Macchia, G., et al. (2022). Stereotactic body radiotherapy in oligometastatic cervical cancer (MITO-RT2/RAD study). Int. J. Gynecol. Cancer , doi:10.1136/ijgc-2021-003237 2-Macchia, G., et al. (2023). Efficacy and safety of stereotactic body radiation therapy in oligometastatic uterine cancer. Int. J. Radiat. Oncol. Biol. Phys. , doi:10.1016/j.ijrobp.2023.04.025