Systemic inflammation response index predicts overall survival in patients undergoing stereotactic radiosurgery for brain metastasis from non-small cell lung cancer

Abstract

This study aimed to evaluate the prognostic value of pre-treatment blood cell counts in patients with brain metastasis (BM) from non-small cell lung cancer (NSCLC) who were treated using linear accelerator (linac)-based stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (fSRT) with a micro-multileaf collimator. Between January 2011 and November 2022, 271 consecutive patients underwent linac-based SRS/fSRT for BM from NSCLC. Thirty patients with insufficient blood test data during this period were excluded from this analysis. Thirty-five patients with steroid intake at the time point of the blood test and 18 patients with higher C-reactive protein were excluded. Thus, 188 patients were eventually enrolled in this study. The median follow-up period after SRS/fSRT was 21 months (range: 0-121 months), and the median survival time after SRS/fSRT was 19 months. Neutrophil-lymphocyte ratio ≥ 1.90, lymphocyte-monocyte ratio ≤ 1.67 and systemic inflammation response index (SIRI) ≥ 2.95 were unfavorable predictors of prognosis for patients who underwent SRS/fSRT for BM from NSCLC. Cox proportional-hazard multivariate analysis revealed that the SIRI was independent prognostic factors for increased risk of death. Thus, simple, less expensive, and routinely performed pre-treatment blood cell count measurements such as SIRI can predict the overall survival of patients treated with SRS/fSRT for BM from NSCLC.

Keywords: brain metastasis; neutrophil–lymphocyte ratio; non-small cell lung cancer; systemic immune-inflammation index; systemic inflammation response index.

Figure 1

Post-radiosurgery overall survival (OS) of the patients with brain metastasis estimated using the Kaplan–Meier method considering each parameter. (A) OS in the entire cohort, (B) neutrophil–lymphocyte ratio (NLR; black line: NLR < 1.90; red line, NLR ≥ 1.90), (C) platelet–lymphocyte ratio (PLR; black line: PLR < 202.2; red line: PLR ≥ 202.2), (D) lymphocyte–monocyte ratio (LMR; black line: LMR < 1.67; red line: LMR ≥ 1.67), (E) systemic immune-inflammation index (SII; black line: SII < 1095; red line: SII ≥ 1095), (F) systemic inflammation response index (SIRI; black line: SIRI <2.95; red line: SIRI ≥2.95).

Figure 2

Freedom of distant failure of the patients with brain metastasis from NSCLC who underwent SRS/fSRT estimated using the Kaplan–Meier method (A) and freedom of local failure of the patients estimated using competing risk survival analysis (B).