When Single-Fraction SRS Still Makes Sense for Resected Brain Metastases

Ayal Aizer, MD, MHS, director of Central Nervous System Radiation Oncology at Brigham and Women’s Hospital and Dana-Farber Cancer Institute and associate professor of radiation oncology at Harvard Medical School, spoke with CancerNetwork ®about which patients may still be candidates for single-fraction stereotactic radiosurgery (SRS) following findings from the phase 3 Alliance A071801 trial (NCT04114981). The study, presented at the 2026 American Society for Radiation Oncology (ASTRO) Annual Meeting, showed improved surgical bed control with postoperative fractionated SRS compared with single-fraction SRS.

Aizer noted that patients on the trial had metastases larger than 2 cm, leaving open whether the results apply to smaller lesions. He added that for patients with a guarded prognosis due to extracranial disease, or those who prefer a single treatment, offering 1 fraction remains reasonable. Although fractionation should be the standard for a typical patient, he said, the preferences of patients, families, and caregivers should still inform care in select cases.

Transcript:

CancerNetwork: Are there cavity sizes or locations where single-fraction SRS still makes sense?

Aizer: Single fraction may still have a role. Patients on this trial had to have a metastasis that was over 2 cm in size. For metastases that are smaller, do the results apply to them? Perhaps or perhaps not. We also have to be cognizant that every patient is different, and there are some patients who have a guarded lifespan. If a patient with a smaller metastasis but a poor prognosis when it comes to extracranial disease says, “I want 1 treatment rather than 3 or 5,” it’s still reasonable to offer that treatment. For your typical patient, fractionation makes a lot of sense and probably should be the standard of care. There could be select patients who didn’t meet the eligibility criteria, or cases based on the preferences of patients, families, and caregivers, where it still seems reasonable to consider 1 fraction.

Reference

Brown PD, Ballman KV, Aizer AA, et al. Alliance A071801 phase III trial postoperative single fraction stereotactic radiosurgery (SRS) vs fractionated SRS (fSRS) for resected brain metastasis. Presented at: 2026 ASTRO Annual Meeting; September 26–30, 2026; Boston, MA. Abstract LBA 01.