# Efficacy of whole-brain radiotherapy with or without simultaneous integrated boost in non-small cell lung cancer with brain metastases: a retrospective analysis

## TL;DR

This study compares whole-brain radiotherapy with and without a dose boost for brain metastases in lung cancer patients, finding similar overall outcomes but better local control in some cases.

## Contribution

The study evaluates the efficacy of WBRT-SIB in NSCLC patients with brain metastases, identifying a subgroup benefit for those with fewer lesions.

## Key findings

- WBRT-SIB showed comparable overall intracranial control to conventional WBRT.
- Patients with fewer than eight brain metastases had significantly better local progression-free survival with WBRT-SIB.
- Anti-angiogenic therapy showed a trend toward improved local tumor control but was not statistically significant.

## Abstract

Whole-brain radiotherapy (WBRT) remains a cornerstone in the management of brain metastases (BMs) from non-small cell lung cancer (NSCLC), and WBRT with simultaneous integrated boost (WBRT-SIB) emerges as a promising strategy that aims to improve local tumor control through dose escalation while maintaining the coverage of subclinical disease offered by WBRT in theory. However, current evidence regarding the efficacy of WBRT-SIB remains inconclusive. This study aimed to compare the intracranial efficacy of WBRT and WBRT-SIB in NSCLC patients with BMs.

Clinical data from 119 patients with NSCLC-BM treated between 2019 and 2025 were retrospectively analyzed. Local progression-free survival (local PFS) was the primary endpoint, while distant PFS and intracranial PFS (iPFS) were secondary endpoints. Propensity score matching (PSM) was performed to balance baseline characteristics. Kaplan–Meier and Cox regression analyses were applied to identify prognostic factors.

No significant differences were observed in local PFS, distant PFS, or iPFS between the WBRT and WBRT-SIB groups, both before and after PSM (all p > 0.05). Subgroup analysis revealed that patients with fewer than eight BMs who received WBRT-SIB achieved significantly longer local PFS compared with those treated with WBRT (p = 0.043), along with a trend toward improved iPFS that did not reach statistical significance (p = 0.066). Furthermore, anti-angiogenic therapy showed a trend as a protective factor for local PFS without reaching statistical significance (p = 0.086).

WBRT-SIB provided comparable overall intracranial control to conventional WBRT but achieved superior local tumor control in patients with limited brain metastases (< 8 lesions). These findings support WBRT-SIB as a promising option for selected NSCLC-BM patients, warranting validation in prospective studies.