Neoadjuvant Chemoimmunotherapy or Chemoradiotherapy in ESCC

Inclusion Criteria: * Be able to understand and voluntarily provide written informed consent before any procedures required for the study are performed. * Age between 18 and 75 years. * Eastern Cooperative Oncology Group (ECOG) performance status score 0-1. * Histologically confirmed esophageal squamous cell carcinoma. * T1N1-3M0 or T2-4aNanyM0 as determined by endoscopic ultrasound (EUS) or magnetic resonance imaging (MRI) and PET/CT. All lesions, including tumor and lymph nodes, were required to be resectable. * Tumors with strong FAPI uptake on baseline PET/CT scan should have a maximum standardized uptake value (SUVmax) ≥5.0. * Subjects were required to provide preoperative paraffin blocks or white slides of tumor tissue, or freshly collected samples, including at least 3 unstained FFPE pathological slides. * Female subjects of childbearing potential must have a urine or serum pregnancy test with a negative result within 3 days before the first dose. If urine testing could not confirm the negative result, serum testing was required. Participants who had sex with an unsterilized male partner were required to use an effective contraceptive method from the time of screening and to agree to continue using a contraceptive method for 120 days after the last dose. Discontinuation of contraception after 120 days was discussed with the investigator. * Unsterilized male subjects who have sex with a female partner of childbearing potential are required to use effective contraceptio…