ESTRO 2025 - Abstract Book

S703

Clinical - CNS

ESTRO 2025

2560

Digital Poster EFFICACY AND SAFETY OF A SECOND COURSE OF WHOLE-BRAIN RADIOTHERAPY FOR MULTIPLE BRAIN METASTASES: KEY DETERMINANTS FOR PATIENT SELECTION Gonçalo Códia Nicolau 1 , Marcos Duarte de Mattos 1 , Laura Ercolin 2 , Danilo Nascimento Salviano Gomes 2 1 Radiotherapy, Hospital de Câncer de Barretos, Barretos, Brazil. 2 Radiotherapy, Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto, Ribeirão Preto, Brazil Purpose/Objective: To evaluate the outcomes of treating multiple brain metastases with whole-brain reirradiation (Re-WBRT) and identify the determining factors to consider for its indication. Material/Methods: This retrospective, single-institution study was conducted by collecting data from patient medical records who underwent Re-WBRT. Characteristics such as sex, primary tumor, treatment regimens, surgery and/or radiosurgery, KPS, DS-GPA, and the extent of systemic disease were evaluated. Statistical analysis was performed using R software (version 4.2.2) with the tidyverse, survival, and survminer packages. Results: The study included 27 patients with a median age of 50 years, 70.4% of whom were female. The most common primary site was the lung (59.2%), followed by the breast (37%), and esophagus (3.8%). Additionally, 44.4% had visceral disease besides brain metastases. Only one patient underwent surgery, and eight patients underwent radiosurgery. The mean KPS at the first WBRT was 80%, with a mean DS-GPA of 11.3 months, and the most common dose regimen was 10x 300 cGy. The median interval between the first and second courses of WBRT was 14.8 months. The mean KPS was 70% and the mean DS-GPA was 6.2 months at Re-WBRT, with the most common regimen being 10x 200 cGy (96.3%). The overall survival was 38.3 months from diagnosis, 23.2 months after the first WBRT, and 3.7 months after the second WBRT. The only factor associated with overall survival was the KPS at the second WBRT, with a median survival of 5.8 months for patients with KPS ≥ 70% and 2.4 months for patients with KPS < 70% (p=0.036). The presence of visceral disease during the first course tended to worsen overall survival (p=0.067). Only two patients (7.4%) had Re-WBRT interrupted due to neurological deterioration. Conclusion: The results of this study suggest that Re-WBRT may be a viable option for patients with multiple metastatic lesions that are not amenable to surgical resection or who do not have access to or indication for radiosurgery, and who experience disease progression after the first course of WBRT. Proper patient selection is crucial, with functional status (KPS) being the primary tool for determining the indication for a second course of WBRT. References: Nieder C, Yobuta R, Mannsåker B. Second Re-irradiation of Brain Metastases: A Review of Studies Involving Stereotactic Radiosurgery. Cureus. 2018 Dec 11;10(12):e3712. doi: 10.7759/cureus.3712. PMID: 30788201 Lucia F, Touati R, Crainic N, Dissaux G, Pradier O, Bourbonne V, Schick U. Efficacy and Safety of a Second Course of Stereotactic Radiation Therapy for Locally Recurrent Brain Metastases: A Systematic Review. Cancers (Basel). 2021 Sep 30;13(19):4929. doi: 10.3390/cancers13194929. PMID: 34638412 Ozgen Z, Atasoy BM, Kefeli AU, Seker A, Dane F, Abacioglu U. The benefit of whole brain reirradiation in patients with multiple brain metastases. Radiat Oncol. 2013 Jul 24;8:186. doi: 10.1186/1748-717X-8-186. PMID: 23879889 Keywords: Whole-brain; Reirradiation; Second course