The value of positron emission tomography scan in predicting pathologic response of non-small cell lung cancer managed by neoadjuvant chemo-immunotherapy.

Background: Neoadjuvant chemo-immunotherapy improves overall survival in resectable stage II-III non-small cell lung cancer (NSCLC). Post-induction re-staging remains challenging and typically relies on contrast-enhanced computed tomography (CT). We assessed the predictive value of Methods: We analyzed all stage II-III, node-positive NSCLC patients from a collected database [2017-2023] who received neoadjuvant chemo-immunotherapy followed by surgery, with pre- and post-induction cancer assessment by Results: Seventeen women and 20 men (mean age 64±7 years) had mostly stage III adenocarcinomas. Open lobectomies (59%) were the most common procedures. Ninety-two percent of resections were R0. Major pathologic response (MPR) and pathologic complete response (pCR) occurred in 51% and 30% of patients, respectively. Mean/max tumor ΔSUV predicted pCR [area under the curve (AUC) =0.8135, P=0.004/AUC =0.8086, P=0.005] but mean/max lymph node ΔSUV predicted pCR better (AUC =0.9044, P<0.001/AUC =0.8990, P<0.001). A 70% decrease in lymph node ΔSUVmax between pre- and post-induction PET/CT predicted pCR with a sensitivity of 88% and a specificity of 78% and correlated with patient overall survival. Conclusions: Significant decrease in lymph node ΔSUVmax on PET/CT after neoadjuvant chemo-immunotherapy strongly predict pCR and overall survival. Further prospective validation is required.