Could time of whole brain radiotherapy delivery impact overall survival in patients with multiple brain metastases?

Brain metastases occur in about 20–40% of advanced cancer patients, with lung cancers accounting for at least half of these occurrences and breast cancers accounting for 15–25% (1,2). Often, brain metastases manifest in upwards of 60–75% of patients as symptoms such as headaches, seizures, sensory deficits, and cognitive decline (1,2). Treatment modalities for brain metastases include neurosurgery, stereotactic radiosurgery (SRS), whole brain radiotherapy (WBRT), and corticosteroid use (1,2). Treatment decisions are based on patient and tumour characteristics. Those with a single brain metastasis or resectable metastases may benefit most from SRS or neurosurgery. On the other hand, symptomatic patients with many brain metastases and for whom the goal of care is often to improve quality of life (QOL), may be treated with WBRT (3). Response to WBRT in terms of symptom improvement ranges from 64% to 85%; however, since patients treated with WBRT often have poor prognosis, progression of brain metastases or other systemic disease may cause death prior to the patient receiving the full benefits of treatment (4). Thus, ways to enhance treatment efficacy for this patient population should be investigated