Focused attention on brain metastases

Abstract

Whole brain radiation therapy (WBRT) has been the standard means to manage brain metastases since the 1950s. Decades of research into fractionation, hypoxia, and radiation sensitisers has not changed this standard approach, which is applied uniformly for one or many metastases, and for tumours with varying radiosensitivity or responsiveness to systemic therapies. Digital imaging improved the diagnosis, treatment, and monitoring of brain metastases. We now know that resection or stereotactic radiosurgery (SRS) of single metastases improves survival when added to WBRT. 1–3 Technologies that enabled easy and repeated SRS for new or multiple metastases led to formal trials of SRS without WBRT. A recent Japanese trial assessed survival using SRS with or without WBRT for patients with one to four brain metastases. 4 Deferring WBRT did not compromise survival, and even though adding WBRT to SRS greatly reduced CNS failures compared with SRS alone, the neurocognitive outcomes were equivalent at 1 year. In this issue of The Lancet Oncology, Chang and colleagues 5 used a similar approach and population to examine neurocognitive outcomes as the primary endpoint. Signifi cant diff erences in learning and memory at 4 months and a substantial diff erence in survival that favoured SRS alone for one to three brain metastases were seen. Again, substantially more salvage procedures were used in the cohort that got SRS alone (83% vs 7%), but 61% of patients in the SRS alone group did not receive WBRT in the fi rst year following the diagnosis of brain metastases.