Can a standardized MRI accurately stage esophageal cancer?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Age 18 to 80 years, inclusive * Histologically confirmed esophageal squamous cell carcinoma based on endoscopic biopsy or other tissue examination * Primary tumor located in the thoracic esophagus * Planned curative esophagectomy * Able to complete the required esophageal MRI examination with diagnostically adequate image quality * Able and willing to provide written informed consent * For Cohort A: no chemotherapy, radiotherapy, immunotherapy, targeted therapy, or other antitumor treatment before MRI; surgery planned within 14 days after MRI; and postoperative pathological T stage expected to be available * For Cohort B: neoadjuvant treatment followed by surgery selected by the clinical multidisciplinary team; baseline MRI completed within 14 days before neoadjuvant treatment; post-treatment MRI completed within 14 days before surgery; and pathological tumor regression grade of the primary tumor bed expected to be available Exclusion Criteria: * Adenocarcinoma, neuroendocrine carcinoma, adenosquamous carcinoma, or another non-squamous histological type * Cervical esophageal cancer, a gastric primary tumor extending into the esophagus, or multiple primary lesions that prevent reliable imaging-pathology matching * Definite distant metastasis, unresectable T4b disease, or another reason that prevents acquisition of a surgical pathological reference standard * Previous esophageal cancer surgery, radiotherapy, or another treatment that substantially altered local esophageal anatomy * Contraindication to MRI, or contraindication to the gadolinium-based contrast agent when the required contrast-enhanced sequences cannot be completed * Severe claustrophobia, inability to follow breathing instructions, or another cause of nondiagnostic image quality that persists after a safe repeat examination * Substantial disease progression, emergency intervention, or off-protocol treatment between MRI and surgery that prevents valid imaging-pathology comparison * Inadequate surgical specimen sampling or inability to determine pathological T stage or pathological tumor regression grade