Timing of Adjuvant Fractionated Stereotactic Radiosurgery Impacts Local Control of Resected Brain Metastases.

TitleTiming of Adjuvant Fractionated Stereotactic Radiosurgery Impacts Local Control of Resected Brain Metastases.
Publication TypeJournal Article
Year of Publication2021
AuthorsO'Brien DARoth, Poppas P, Kaye SM, Mahase SS, An A, Christos PJ, Liechty B, Pisapia D, Ramakrishna R, A Wernicke G, Knisely JPS, Pannullo S, Schwartz TH
JournalPract Radiat Oncol
Date Published2021 Feb 09

OBJECTIVE: For resected brain metastases (BM), stereotactic radiosurgery (SRS) is often offered to minimize local recurrence (LR). Although the aim is to deliver SRS within a few weeks of surgery, a variety of socioeconomic, medical, and procedural issues can cause delays. We evaluated the relationship between timing of postoperative SRS and LR.

METHODS: We retrospectively identified a consecutive series of BM patients managed with resection and SRS or fractionated SRS at our institution from 2012-2018. We assessed the correlation between time to SRS, and other demographic, disease, and treatment variables, and LR, local recurrence-free survival (LRFS), distant recurrence (DR), distant recurrence-free survival, and overall survival (OS).

RESULTS: 133 patients met inclusion criteria. Median age was 64.5 years. Approximately half of patients had a single BM, and median BM size was 2.9 cm. Gross total resection (GTR) was achieved in 111 (83.5%) patients, and >90% received fractionated SRS. Median time to SRS was 37.0 days and LR rate was 16.4%. Time to SRS was predictive of LR. Median time from surgery to SRS was 34.0 days for patients without LR, vs. 61.0 days for those with LR (p<0.01). LR was 2.3% with SRS administered ≤4 weeks postoperatively, compared to 23.6% if >4 weeks (p<0.01). LRFS was also improved for patients who had SRS at ≤4 weeks (p=0.02). Delayed SRS was also predictive of DR (p=0.02), but not OS.

CONCLUSIONS: In this retrospective study, the strongest predictor of LR following postoperative SRS for BM was time to SRS, and a cut-off of 4 weeks was a reliable predictor of recurrence. These findings merit investigation in a prospective, randomized trial.

Alternate JournalPract Radiat Oncol
PubMed ID33578001