Study on the effects of estimated dose of radiation to immune cells and CBC parameters on the prognosis of patients with locally advanced non-small cell lung cancer undergoing radiotherapy.

BACKGROUND: Locally advanced non-small-cell lung cancer (LA-NSCLC) is a subtype of lung cancer with substantial heterogeneity in clinical prognosis. Immune injury induced by radiotherapy exposure is a critical factor affecting treatment response and long-term outcomes. This study enrolled patients with LA-NSCLC to investigate the prognostic value of complete blood count (CBC) parameters combined with the estimated dose of radiation to immune cells (EDRIC), aiming to facilitate precision prognostic stratification and tailored treatment strategies in clinical practice. MATERIALS AND METHODS: This study included 329 patients with LA-NSCLC who received radiotherapy (RT) at our institution. Serial CBC measurements were obtained pre-RT, weekly during RT, and 1-month post-RT. EDRIC was calculated based on the model developed by Jin et al. and improved by Ladbury et al. We subsequently evaluated the associations of EDRIC and CBC parameters with overall survival (OS), local recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), and progression-free survival (PFS). RESULTS: Univariate and multivariate analyses demonstrated that EDRIC, together with week 3 platelet-to-lymphocyte ratio (PLR), was significantly associated with OS, LRFS, DMFS, and PFS (P < 0.05). In multivariate models, neither MHD, MLD, nor MBD was significantly associated with survival outcomes, regardless of the inclusion of EDRIC; however, EDRIC demonstrated a significant correlation. For OS discrimination, Harrell's C-index reached 0.622 for the EDRIC-alone model, 0.734 for the model integrating clinical covariates and CBC markers, and 0.740 for the combined model incorporating clinical features, serial CBC indices and EDRIC. CONCLUSIONS: EDRIC is an independent prognostic biomarker for OS, LRFS, PFS and DMFS in LA-NSCLC patients undergoing definitive thoracic (chemo)radiotherapy. Week 3 PLR also independently predicts all four survival endpoints. Compared with the EDRIC-only model, the integrated model incorporating pretreatment EDRIC, clinical variables, and on-treatment inflammatory markers (NLR and PLR) yields more accurate and comprehensive prognostic stratification for patients with LA-NSCLC.