In a systematic review and meta-analysis reported in The Lancet Oncology, Gaebe et al found that stereotactic radiosurgery (SRS) was associated with “equitable survival” compared with whole-brain radiotherapy (WBRT) in the first-line treatment of intracranial metastatic disease in patients with small cell lung cancer (SCLC).
As stated by the investigators, “Patients with SCLC are at high risk for intracranial metastatic disease. Although SRS has supplanted WBRT as first-line treatment for intracranial metastatic disease in most solid cancers, WBRT remains first-line treatment for intracranial metastatic disease in patients with SCLC. We aimed to evaluate the efficacy of SRS in comparison with WBRT and assess treatment outcomes following SRS.”
Study Details
The meta-analysis for comparison of SRS and WBRT included seven studies. Data on overall survival following SRS were available from 14 additional single-group studies. The primary outcome measure was overall survival, presented as pooled hazard ratios (HRs) through random-effects meta-analysis for studies comparing SRS with WBRT with or without SRS boost, and as median for single-group SRS studies.
Key Findings
In seven studies with a total population of 18,130 patients, overall survival was improved with SRS vs WBRT with or without SRS boost (HR = 0.85, 95% confidence interval [CI] = 0.75–0.97).
In seven studies with a total population of 16,961 patients, overall survival was improved with SRS vs WBRT alone (HR = 0.77, 95% CI = 0.72–0.83).
In four studies with a total population of 1,167 patients, no significant difference in overall survival was observed for SRS vs WBRT plus SRS boost (HR = 1.17, 95% CI = 0.78–1.75).
Between-study heterogeneity was high when pooled among all comparative studies (I² = 71.9%, 95% CI = 48.3%–84.7%).
Analysis of 14 single-group studies with a total population of 1,682 patients showed pooled median overall survival with SRS of 8.99 months (95% CI = 7.86–10.16 months). Local intracranial control rates were 81% and 78% at 6 and 12 months, and distant intracranial control rates were 66% and 58% at 6 and 12 months.
The investigators concluded, “Our findings suggest that SRS can achieve equitable survival compared with WBRT in patients with SCLC and intracranial metastatic disease, challenging previous reservations regarding the use of SRS in these patients given the perceived risk of rapid intracranial progression… Future prospective studies should focus on tumor burden and differences in local and distant intracranial progression between WBRT-treated and SRS-treated patients with SCLC.”
Sunit Das, MD, PhD, of the Department of Surgery, St. Michael’s Hospital, University of Toronto, is the corresponding author for The Lancet Oncology article.
Disclosure: The investigators reported that there was no funding for the study. For full disclosures of the study authors, visit thelancet.com.
