M. Harat, M. Blok, J. Kowalewska
Nov 9, 2020
Stereotactic radiosurgery (SRS) in patients with risk factors other than the number of intracranial metastases remains controversial. Here we define factors related to early death after SRS alone and compared SRS alone with WBRT in high-risk patients. The aim of our study was to verify if optimal brain treatment may extend survival in patients with poor prognosis and select optimal candidates. In this prospectively collected data, 180 patients with brain metastases and adverse prognostic factors not previously treated with WBRT were analyzed. SRS patients were divided into training (n=82) and validation (n=48) cohorts and compared to retrospective data of WBRT patients (n=50). Overall survival (OS) and probability of 3-month survival in relation to risk factors were defined by univariable and multivariable analyses. In multivariable analysis, GPA (OR 0.44, 95%CI 0.21-0.95; p=0.001), extensive extracranial disease (OR 0.13, 95%CI 0.02-0.66; p=0.013), and serious neurological deficits (OR 0.13, 95%CI 0.04-0.45; p=0.001) were associated with early death. If one factor was favorable, 73% (training) and 92% (validation) of patients survived 3 months. Patients with coexisting GPA< 2, serious neurological deficits, and extracranial extensive disease had the highest risk of death within 3 months (AUC 0.822 training; 0.932 validation). Median survival of the WBRT and SRS cohorts was 86 days (interquartile range (IQR): 38-172 days) and 201 days (IQR: 86-not reached), respectively (p< 0.0001). OS in very high-risk patients (GPA< 2) was significantly longer in the SRS vs. WBRT group (123 vs. 58 days; p=0.008). Extracranial oligometastatic disease, intact neurological status, or GPA ≥2 should be present to justify SRS in patients with 1-10 brain metastases. SRS alone is a viable treatment option in comparison to WBRT and most importantly survival benefits may be expected even for high-risk patients (GPA< 2).