An Exploratory Clinical Study of Accurate Efficacy Assessment of Neoadjuvant Immunotherapy in Locally Advanced Esophageal Squamous Cell Carcinoma Based on 68Ga-FAPI ([68Ga] Fibroblast Activation Protein Inhibitor)/¹⁸F-FDG (2-Deoxy-2-[¹⁸F]Fluoro-D-glucose) Dual Imaging

This study will evaluate whether two positron emission tomography/computed tomography (PET/CT) scans performed before treatment-68Ga-FAPI and 18F-FDG-can help predict how well patients with resectable, locally advanced thoracic esophageal squamous cell carcinoma respond to immunotherapy plus chemotherapy given before surgery. The study hypothesis is that information from the two scans can identify patients who are unlikely to have a pathologic complete response (pCR), meaning no remaining cancer in the removed esophagus or lymph nodes, and that retlirafusp alfa may improve pathologic response compared with adebrelimab when each is combined with chemotherapy in these patients. This study has two stages and plans to enroll 92 adults aged 18 to 75 years with previously untreated, stage II to IVA, resectable thoracic esophageal squamous cell carcinoma. All participants will undergo both PET/CT scans before treatment.