Results from the randomized Alliance A071801 trial, presented at the ASTRO annual meeting, show that fractionated stereotactic radiosurgery (SRS) improves surgical-bed control compared with single-fraction SRS for patients who have had a large brain metastasis resected. The 1-year local control rate was 87% versus 81%, and fractionated SRS reduced the hazard of surgical-bed failure by 47%.
Secondary endpoints also favored fractionated treatment. Median overall survival was 28.6 months versus 20.2 months, and more patients remained free from salvage whole-brain radiotherapy at 1 year (94% versus 84%). Rates of radiation necrosis and cerebral edema were similar between the two groups.
The trial's lead author, Ayal Aizer, said fractionated SRS should now be considered the standard of care after resection of larger brain metastases, citing the move from retrospective data to phase III evidence. ASTRO discussant Rupesh Kotecha agreed that fractionated radiosurgery is the new standard if postoperative external beam radiotherapy is chosen, but cautioned that the overall survival difference requires further study to explore potential explanations.