Safety and efficacy of delivering systemic treatments concomitantly with whole-brain radiotherapy: a prospective, observational, single-institution study.

AIM: The aim of our study was to evaluate the safety and efficacy of delivering systemic treatments concurrently with whole-brain radiotherapy (WBRT). METHODS: A single-institution, prospective observational study was conducted in Athens, Greece, including 99 patients treated with WBRT for brain metastases from September 2017 until October 2019, and with a follow-up period extending to March 2025. The study endpoints included overall survival (OS) for all causes of death, time to intracranial progression (TTICP), and serious acute toxicities. RESULTS: The median OS from all causes of death was 6 months [95% confidence interval (CI): 4.7-7.3]. Concomitant systemic therapy reduced the risk of death (p = 0.005), and the presence of systemic metastases (p = 0.009) increased the risk of death for patients with brain metastases treated with whole brain radiotherapy. The median TTICP was 10 months (95% CI: 3.3-16.6), with a more protracted fractionation and a larger number of brain metastases being prognostic of an increase in the TTICP. Acute severe toxicity was observed in 16.2% of patients, with no statistically significant difference between concurrent and no systemic therapy groups, and with no treatment interruptions in patients treated concurrently. CONCLUSIONS: This study showed that there is no serious toxicity from the combination of systemic therapy with WBRT, and that the OS and the TTICP are not compromised with their concurrent delivery.