Fractionated Stereotactic Radiosurgery Following Surgery for Brain Metastases: A Single Australian Centre Experience and Literature Review.

Abstract PurposeThe aim of this study was to evaluate the efficacy and safety of adjuvant multifractionated stereotactic radiotherapy (SRS) for patients with resected brain metastases (BM). Methods and MaterialsWe retrospectively assessed 54 patients with brain metastases who underwent surgery and postoperative SRS in a single institution between January 2016 and June 2021. All but one patient were treated with hypo fractionated stereotactic radiotherapy (HF-SRT) with doses ranging from 30 Gy in 5 fractions, 25 Gy in 5 fractions, or 27 Gy in 3 fractions. The primary outcome for this study was local control (LC) within the resection cavity. The secondary endpoints were overall survival (OS), distant brain failure (DBF), leptomeningeal disease (LMD), and brain radionecrosis (RN). ResultsThe median follow-up was 14.9 months. Local control was 90.6% at 6 months and 82.1% at 12 months. The six and twelve-month estimates of DBF were 19.2% and 25.9%, respectively. Seven patients (12.9%) experienced both local and distant failures, including 2 cases with leptomeningeal disease. At the time of final analysis, median times to local failure, DBF and LMD were not reached. OS rates at 6 months and 12 months were 80.8% and 56.6%, respectively. RN was present in 4 cases (7.4%). ConclusionsThis single-institution retrospective study shows that postoperative HF-SRT in patients with BM seems to be associated with favourable outcomes for LC and relatively low-risk of RN.