High Biologically Effective Dose Radiotherapy for Brain Metastases May Improve Survival and Decrease Risk for Local Relapse Among Patients With Small-Cell Lung Cancer: A Propensity-Matching Analysis

Abstract

<jats:p> To evaluate whether high biologically effective dose (BED) radiotherapy improves local control and survival outcomes for patients with brain metastases (BMs) from small-cell lung cancer (SCLC) and to determine possible prognostic factors. From January 1998 to June 2018, 250 patients with BM from SCLC were retrospectively analyzed. The Cutoff Finder program was used to classify patients by BED. Overall survival (OS) and BM progression-free survival (BM-PFS) were analyzed using the Kaplan-Meier method and log-rank test. A Cox regression model was used to calculate the hazard ratio and 95% CI for prognostic factors for OS among the study population and propensity score (PS)–matched patients. A BED of 47.4 was taken as the optimal cutoff value. Both OS and BM-PFS were significantly improved in the high-BED (&gt;47.4 Gy) than in the low-BED (≤47.4 Gy) group (median OS: 17.5 months vs 9.5 months, P &lt; .001, median BM-PFS: 14.4 months vs 8.3 months, P &lt; .001). Biologically effective dose ( P &lt; .001), Eastern Cooperative Oncology Group performance status ( P = .047), smoking ( P = .005), and pleural effusion ( P = .004) were independent prognostic factors for OS. Propensity score matching with a ratio of 1:2 resulted in 57 patients in the high-BED group and 106 patients in the low-BED group. In the PS-matched cohort, OS and BM-PFS were significantly prolonged in the high-BED group compared with the low-BED group ( P &lt; .001). Biologically effective dose &gt;47.4 Gy improves survival among patients with BM from SCLC. Eastern Cooperative Oncology Group score, smoking, and pleural effusion independently affect OS of SCLC patients with BM. </jats:p>

Individualized Nomogram for Predicting Survival in Patients with Brain Metastases After Stereotactic Radiosurgery Utilizing Driver Gene Mutations and Volumetric Surrogates

“…Single SRS was conducted in 189 patients while FSRS (2–3 fx) in 167 patients. The median biologically effective dose (BED) of radiation was 41.6 Gy (IQR 41.6–50.4) for the α/β value of 10 ( 16 ). In the overall cohort, the median OS was 17.7 months (95% CI 15.5–19.9).…”

A Study of Dose Painting with IMRT Guided by Perfusion-weighted Magnetic Resonance Imaging for Brain Metastases

“…Therefore, RT is an irreplaceable treatment for BM [3,4,22,23] . However, an increased radiation dose, particularly to vascular endothelial cells and glial cells, is associated with increased toxicity and reduced tolerance to treatment [24] .…”

“…BM is a signi cant health problem whose incidence is increasing, and the median survival time is only 1-2 months without treatment [1,19−21] . Numerous studies have indicated that increasing the dose of RT signi cantly improves the local control of BM, and some patients have achieved long-term survival [22,23] .…”

Radioimmunotherapy for Brain Metastases: The Potential for Inflammation as a Target of Choice

“…Additionally, the injected activity or number of cycles could be tailored to reach the best TCP, whilst lowering the NTCP as in WBRT. For instance, the TCP model of WBRT is based on a biologically effective dose of about 40 Gy ( 38 ). Usually, a fractionation of 10 times 3 Gy is delivered to the patient after a CT planning scan.…”