Alliance A071801 Trial Supports Fractionated SRS After Surgery
- Fractionated stereotactic radiosurgery significantly improves local control in the surgical bed compared to single-fraction treatment for patients with resected brain metastases, according to findings from the Alliance A071801...
- Brown and colleagues, the Alliance A071801 phase 3 trial evaluated postoperative single-fraction stereotactic radiosurgery against fractionated stereotactic radiosurgery for resected brain metastases.
- Although final time-to-event analyses are pending, researchers observed no meaningful differences in toxicity rates during preliminary evaluations.
Fractionated stereotactic radiosurgery significantly improves local control in the surgical bed compared to single-fraction treatment for patients with resected brain metastases, according to findings from the Alliance A071801 phase 3 trial. While single-fraction stereotactic radiosurgery has historically served as the default standard of care following the removal of larger brain metastases exceeding 2 centimeters, trial results indicate that extending radiation delivery across three to five days yields superior tumor control without increasing radiation necrosis rates.
Alliance A071801 Trial Results Show Better Local Control Without Added Toxicity
Led by Dr. Brown and colleagues, the Alliance A071801 phase 3 trial evaluated postoperative single-fraction stereotactic radiosurgery against fractionated stereotactic radiosurgery for resected brain metastases. The trial results established better local control in the surgical bed for patients receiving fractionated treatment. Crude rates of radiation necrosis remained comparable between the two arms, averaging between 10% and 15% of patients in both groups.
Although final time-to-event analyses are pending, researchers observed no meaningful differences in toxicity rates during preliminary evaluations. Despite the proven benefits of fractionation for typical patients, single-fraction treatment may still be considered for individuals with smaller metastases under 2 centimeters or those with guarded lifespans who prefer a single treatment session.
Tile-Based Radiation Therapy Offers Alternative Approach in ROADS Trial
Sharing findings on X from the Journal of Clinical Oncology, Ilyas Sahin, assistant professor of medicine at Harvard Medical School and medical oncologist at Massachusetts General Hospital, noted that the ROADS trial demonstrated a one-year surgical-site recurrence rate of 1.3% for tile-based radiation compared to 15.4% for traditional postoperative stereotactic radiation.
The ROADS trial also reported a median overall survival of 42.5 months for the cesium-131 tile arm versus 17.6 months for the stereotactic radiation arm, though overall survival functioned as a secondary endpoint with relatively short follow-up.
Unresected Metastases and Preoperative Radiation Direct Future Research
Future clinical trials will determine whether the efficacy of fractionation observed in surgical cavities applies to intact, unresected brain metastases. Patients enrolled in the Alliance trial with up to three unresected brain metastases showed an encouraging trend toward better local control with fractionated stereotactic radiosurgery, yielding a P value of .06. A completed phase 3 NRG study, registered as NCT06500455, is slated to provide definitive answers regarding fractionation in intact brain metastases.
Researchers are also investigating whether preoperative stereotactic radiation outperforms postoperative delivery by minimizing meningeal seeding and reducing necrosis. Ongoing randomized trials continue to evaluate safety and efficacy data for preoperative approaches.