SRT Radiation Shows Superiority Over WBRT for Brain Metastases

For patients with brain metastases, radiation therapy is a cornerstone of management. While stereotactic radiation (SRT) has shown quality of life benefits over whole brain radiation therapy (WBRT) for patients with a limited number of metastases (≤4), comparative data for those with more extensive disease (5–20 metastases) has been lacking. Furthermore, despite hippocampal avoidance WBRT (HA-WBRT) demonstrating superiority over traditional WBRT, its comparison to SRS/SRT was unstudied.

To address this, a multicenter, phase 3 randomized trial was conducted comparing SRT to HA-WBRT in patients with 5 to 20 brain metastases from solid primary tumors, excluding small cell lung cancer. The primary end point focused on patient-reported symptom severity and functional interference over six months using the validated MD Anderson Symptom Inventory–Brain Tumor (MDASI-BT) module.

"Really, at its core, we wanted to compare these 2 treatments and see which was better for patients in terms of really what matters to most patients, which is their symptom burden, how much those symptoms interfere with their daily function, how active they are, how well they can complete their activity," said Ayal Aizer, MD, brain radiation oncologist at Brigham and Women's Hospital and Dana-Farber Cancer Institute and first author on the study, said in an interview with Targeted Oncology.

From April 2017 to May 2024, 196 eligible patients were enrolled, with 98 in each arm. The median number of brain metastases was 14. Analysis of the primary end point revealed significantly lower symptomatology and functional interference in the SRS/SRT arm compared to the HA-WBRT arm (difference –1.06, P <.001). Specifically, SRT resulted in lower symptom severity (difference –0.62, P <.001) and less interference (difference –1.50, P <.001) posttreatment relative to baseline. Importantly, there was no significant difference in median overall survival between the 2 arms (8.3 months for SRT vs 8.5 months for HA-WBRT, P =.30).

These findings suggest that for patients with 5 to 20 brain metastases, SRT offers a superior quality of life, as evidenced by reduced symptoms and functional interference, without compromising overall survival. This supports SRT as a strong candidate for the standard of care in this patient population.