Top Line: Increasing the number of brain metastases certainly increases complexity of radiosurgical planning, but can it inform survival expectations?
The Study: This is a single-institution retrospective series of 557 patients with ≥5 newly-diagnosed brain metastases treated with Gamma Knife radiosurgery between 2015–2022. Investigators ask how much, if at all, lesion count matters in the era of increasingly CNS-active systemic therapy. Median overall survival was 11 months, with 65% alive at 6 months, 46% at 12 months, and 29% at 24 months. Ultimately, lesion count (5–9 vs ≥10) was not associated with survival on multivariable analysis. What was? Interestingly, escalation after radiosurgery to a more CNS-active systemic regimen, as defined by NCCN guidelines for brain metastasis (HR 0.52). Performance status and systemic disease status remained obvious tells, as well. Roughly half experienced CNS progression by 12 months, and the median survival free from whole-brain radiation was 9 months. One standout for patients with ≥10 lesions was a significantly higher rate of leptomeningeal failure (19%).
TBL: This data was used to create a handy nomogram to estimate survival free from whole-brain radiation at 6 and 12 months to help identify the patients who will meaningfully benefit from the painstaking radiosurgical planning for multiple brain mets. | Beckham, JNCCN 2026
The Study: This is a single-institution retrospective series of 557 patients with ≥5 newly-diagnosed brain metastases treated with Gamma Knife radiosurgery between 2015–2022. Investigators ask how much, if at all, lesion count matters in the era of increasingly CNS-active systemic therapy. Median overall survival was 11 months, with 65% alive at 6 months, 46% at 12 months, and 29% at 24 months. Ultimately, lesion count (5–9 vs ≥10) was not associated with survival on multivariable analysis. What was? Interestingly, escalation after radiosurgery to a more CNS-active systemic regimen, as defined by NCCN guidelines for brain metastasis (HR 0.52). Performance status and systemic disease status remained obvious tells, as well. Roughly half experienced CNS progression by 12 months, and the median survival free from whole-brain radiation was 9 months. One standout for patients with ≥10 lesions was a significantly higher rate of leptomeningeal failure (19%).
TBL: This data was used to create a handy nomogram to estimate survival free from whole-brain radiation at 6 and 12 months to help identify the patients who will meaningfully benefit from the painstaking radiosurgical planning for multiple brain mets. | Beckham, JNCCN 2026