Person:

Diao, Kevin

Background: Stereotactic radiosurgery (SRS) alone is an increasingly accepted treatment for brain metastases, but requires adherence to frequently scheduled follow-up neuroimaging due to risk of distant brain metastasis. The effect of disparities in access to follow-up care on outcomes after SRS alone is unknown. Methods: This retrospective study included 153 brain metastasis patients treated consecutively with SRS alone from 2010 through 2016 at an academic medical center and a safety net hospital located in Los Angeles, California. Outcomes included neurologic symptoms, hospitalization, steroid use and dependency, salvage SRS, salvage whole brain radiotherapy (WBRT), salvage neurosurgery, and overall survival (OS). Results: Of 153 patients, 93 were private hospital patients and 60 were safety net hospital patients. Median follow-up time was 7.7 months. Safety net hospital patients received fewer follow-up neuroimaging studies (1.5 safety net, 3 private; p=0.008). In multivariable analysis, safety net hospital setting was a significant risk factor for salvage neurosurgery (HR 13.65, p<0.001), neurologic symptoms (HR 3.74, p=0.002), and hospitalization due to brain metastases (HR 6.25, p<0.001). More clinical visits were protective for hospitalization due to brain metastases (HR 0.75, p=0.002) while more neuroimaging studies were protective for death (HR 0.65, p<0.001). Conclusions: Safety net hospital patients with brain metastases treated with SRS alone had fewer follow-up neuroimaging studies and higher risk of neurologic symptoms, hospitalization for brain metastases, and salvage neurosurgery compared to private hospital patients. Clinicians should consider practice setting and patient access to follow-up care when deciding on the optimal strategy for treatment of brain metastases.

Abstract 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.