Prognostic Value of 18F-FDG PET/CT in Neoadjuvant PD-1 Inhibitor-treated NSCLC: A Five-year Follow-up Study.

Background: Neoadjuvant immunotherapy has shown promising short-term outcomes of perioperative treatments for resectable non-small cell lung cancer (NSCLC) and is expected to release long-term survival benefits. Here, we reported the long-term prognostic value of 18F-FDG PET/CT over ∼a 5-year follow-up.

Patients And Methods: A total of 35 patients with NSCLC (29 males and 6 females; median age, 62 y) received 2 doses of sintilimab, followed by complete tumor resection and PET/CT scans at baseline and post-neoadjuvant stages. We investigated the prognostic value of PET/CT for overall survival (OS) and progression-free survival (PFS), focusing on metabolic parameters of primary tumors, mediastinal lymph nodes, lymphoid organs, and immune-related adverse events on imaging.

Results: During a median follow-up of 62.6 months, patients with low primary tumor metabolism (SULmax ≤6.6, SULpeak ≤4.0/3.9, or SULmean ≤2.7) at post-neoadjuvant scan were alive and disease-free, demonstrating improved OS (P = 0.07, 0.07, and 0.09) and significantly enhanced PFS (P = 0.01, 0.02, and 0.02); those with low metabolic tumor volume ≤49.3 or total lesion glycolysis ≤41.0 at post-neoadjuvant scan also had significantly improved OS (P = 0.03 and 0.05). Patients with low lymph node metabolism (SULmax ≤4.6) at baseline scan had significantly improved PFS (P = 0.04).

Conclusions: This is the first study to report the long-term prognostic value of 18F-FDG PET/CT for resectable NSCLC after neoadjuvant immunotherapy. Low primary tumor metabolism at post-neoadjuvant scan and low lymph node metabolism at baseline scan are promising prognostic markers for improved clinical outcomes.