Molecular imaging research on 18F-FDG PET/CT and biomarker analysis predicts the pathological response to neoadjuvant camrelizumab combined with chemotherapy for resectable stage IIIA-IIIB NSCLC.

Objective This study aims to predict the pathological response of patients with non-small cell lung cancer (NSCLC) in prospective trials of neoadjuvant camrelizumab combined with chemotherapy by integrating clinical characteristics, PET-associated parameters, and hematological indicators. Methods A prospective analysis was conducted among 24 patients undergoing surgery after neoadjuvant camrelizumab plus chemotherapy. ¹⁸ F-Fluorodeoxyglucose (FDG) scans were performed before and after neoadjuvant therapy (pre-NAT, post-NAT). Tumor and secondary lymphoid organ metabolic parameters, along with circulating inflammatory and immune indicators, were measured and correlated with pathological response. Receiver operating characteristic (ROC) curve was used to assess biomarkers’ predictive accuracy. Results Major pathological response (MPR) and pathological complete response (pCR) was achieved in 45.8% (11/24) and 33.3% (8/24) of patients. Before treatment, patients who achieved a pCR had significantly greater SUVmax values ( p  = 0.011) than non-pCR patients did. After treatment, the MPR group exhibited significantly lower SUVmax values than did the non-MPR group ( p  = 0.048). The rate of change in the SUVmax (ΔSUVmax%) differed significantly between pCR and non-pCR groups ( p  = 0.019) and between MPR and non-MPR groups ( p  = 0.013). After NAT, the lymph nodes SUVmax in the ypN0 group was significantly lower than that in the ypN + group ( p  = 0.032). ROC analysis indicated that pre-NAT SUVmax and ΔSUVmax% best distinguished pCR and MPR patients, respectively, with AUCs of 0.82 ( p  = 0.012) and 0.80 ( p  = 0.014). Conclusion The pre-NAT SUVmax and ΔSUVmax% are promising biomarkers for predicting pathological response to neoadjuvant camrelizumab and chemotherapy. ClinicalTrials.gov ID NCT06241807