One and done.

The bad news continues for whole brain radiation (WBRT). Once the stalwart of palliative treatment for brain metastases, it is increasingly supplanted by more focal stereotactic radiosurgery (SRS). Last year’s randomized controlled trial in JAMA showed no improvement in survival and worse cognitive deterioration when WBRT was given after SRS for limited brain mets, even though WBRT reduced the rate of subsequent mets. Two RCTs (1, 2) published last week in Lancet Oncology offer additional insight into the management of resected brain mets. We know that resection of a single brain met prolongs survival, and adjuvant radiation further improves local control. Over the ensuing decades, the question has become: SRS or WBRT after surgery? Trial #1 compared post-op SRS to observation and found a big increase in 1 year local control (43% → 72%). Trial #2 compared post-op SRS to WBRT and found similar overall survival. As expected, cognition was better after SRS. Unexpectedly, a local control advantage was seen with WBRT (81% vs 61% with SRS). The thought is that the single treatment doses used in the study were insufficient for larger cavities which would have been better addressed with hypofractionated (3-5 treatment) SRS regimens. So even if it’s one (to five) and done, these trials likely cement SRS as the standard-of-care for resected brain mets.