The Influence of Stereotactic Body Radiotherapy (SBRT) on Biomarker Profiles in Lung Cancer: A Detailed Overview

Background: Stereotactic Body Radiation Therapy (SBRT) represents the standard treatment for inoperable early-stage non-small cell lung cancer (NSCLC) and is increasingly utilized for oligometastatic disease. Its distinct radiobiological profile, involving high doses per fraction, triggers complex tumor-killing effects and systemic biological reactions not fully detectable through conventional imaging.Objective: This review aims to summarize and critically assess current evidence regarding dynamic alterations in circulating, tissue, and imaging biomarkers after SBRT for lung cancer, and to explore their clinical significance.Methods: A narrative synthesis of scientific literature from PubMed, Scopus, and Google Scholar was conducted, focusing on studies published between ۲۰۰۵ and ۲۰۲۴. Key search terms included "SBRT," "SABR," "lung cancer," "biomarker," "ctDNA," "immunotherapy," "cytokines," and "radiation pneumonitis."Results: SBRT prompts a rapid, biphasic shift in tumor-derived biomarkers such as circulating tumor DNA (ctDNA), characterized by an initial post-treatment surge followed by reduction in responders. It significantly influences the immune system, inducing immunogenic cell death, expanding tumor-specific T-cell populations, and increasing checkpoint molecule expression like PD-L۱. Additionally, SBRT modifies levels of cytokines (e.g., IL-۶, TGF-β) and angiogenic factors (e.g., VEGF), which correlate with both treatment effectiveness and side effects like radiation-induced lung injury. Certain genetic polymorphisms also appear promising for predicting toxicity risk.Conclusion: SBRT induces a dynamic and multifaceted change in the biomarker profile of lung cancer patients. These biomarkers offer considerable potential for personalizing treatment, predicting outcomes, monitoring response, and rationally planning combination therapies, especially with immunotherapy. Future prospective and validated studies are necessary to integrate these findings into clinical practice.

کلیدواژه ها:

Stereotactic body radiotherapy ، Biomarker ، Lung cancer