The growing importance of lesion volume as a prognostic factor in patients with multiple brain metastases treated with stereotactic radiosurgery.
Stereotactic Radiosurgery (SRS) is considered standard of care for patients with 1-3 brain metastases (BM). Recent observational studies have shown equivalent OS in patients with 5+ BM compared to those with 2-4, suggesting SRS alone may be appropriate in these patients. We aim to review outcomes of patients treated with SRS with 2-4 versus 5+ BM. This analysis included consecutive patients from 1994 to 2015 treated with SRS. Of 1017 patients, we excluded patients with a single BM and patients without adequate survival data, resulting in 391 patients. All risk factors were entered into univariate analysis using Cox proportional hazards model, and significant factors were entered into multivariate analysis (MVA). We additionally analyzed outcomes after excluding patients with prior surgery or whole-brain radiotherapy (WBRT). Median follow-up was 7.1 months. Median KPS was 90, mean age was 59, and most common histologies were melanoma and lung. Median tumor volume was 3.41 cc. Patients with 2-4 BM had a median OS of 8.1 months compared to 6.2 months for those with 5+ BM (P = 0.0136). On MVA, tumor volume, KPS, and histology remained significant for OS, whereas lesion number did not. Similar results were found when excluding patients with prior surgery or WBRT. Rather than lesion number, the strongest prognostic factors for patients undergoing SRS were tumor volume >10 cc, KPS, and histology. BM number may therefore not be the most important criterion for candidacy for SRS. Patients with 5 or more BM should be considered for SRS.
['Routman|David M|DM|0000-0002-2768-003X', 'Bian|Shelly X|SX|', 'Diao|Kevin|K|0000-0002-7092-6162', 'Liu|Jonathan L|JL|', 'Yu|Cheng|C|', 'Ye|Jason|J|', 'Zada|Gabriel|G|', 'Chang|Eric L|EL|']
D000293:Adolescent D000328:Adult D000368:Aged D000369:Aged, 80 and over D001932:Brain Neoplasms D005260:Female D006801:Humans D008297:Male D008875:Middle Aged D009362:Neoplasm Metastasis D011379:Prognosis D016634:Radiosurgery D012189:Retrospective Studies D012307:Risk Factors D047368:Tumor Burden D055815:Young Adult
Brain metastases stereotactic radiosurgery tumor volume lesion number whole-brain radiation therapy