2. M ETHODS Median dose was 22Gy (range: 1000-2800) in 1 to 5 fractions Median treatment volume was 12.6 cc (range: 0.6- 51.1). Assessed for eligibility (n=108) Large brain metastasis (>3 cm on pre-operative MRI) Index lesion treated with resection followed by SRS Biopsy-proven systemic cancer Excluded (n=6) Patients treated with SRS >3 months after resection (n=6) 102 patients with 103 large brain metastases analyzed 87 patients (88 metastases) with follow-up imaging included in LC and DBF analysis 102 patients included in OS analysis

3. R ESULTS Risk Stratification for Freedom from Distant Brain Failure. (A) Systemic Disease Control, (B) Non- melanoma primary (C) Number of Brain Metastases (D) Combined Risk Stratification.

4. C ONCLUSIONS Postoperative SRS to the resection cavity following craniotomy is a safe & effective local treatment for large brain metastases independent of extent of resection, size of resection cavity, histology, number of metastases or systemic disease control. Patients with controlled systemic disease and ≤ 3 brain metastases are ideal candidates for postoperative SRS with significantly lower rates of DBF.