Standardized MRI and Structured Reporting for Esophageal Squamous Cell Carcinoma

Development and Multicenter Validation of Standardized MRI Acquisition and Structured Reporting for Primary Esophageal Squamous Cell Carcinoma: A Dual-Cohort Study of T Staging and Tumor Regression Grading

This prospective, multicenter diagnostic accuracy study will develop and validate a standardized 3.0-T magnetic resonance imaging (MRI) acquisition protocol and structured reporting system for primary esophageal squamous cell carcinoma (ESCC). Approximately 500 adults scheduled for curative esophagectomy will be enrolled consecutively into two clinically defined cohorts. In Cohort A, patients proceeding directly to surgery will have MRI-based T staging compared with postoperative pathological T stage. In Cohort B, patients receiving neoadjuvant therapy before surgery will undergo paired MRI assessment, and MRI-based tumor regression grade will be compared with pathological tumor regression grade in the resected primary tumor bed. Imaging will be independently assessed by two radiologists, with adjudication by a third reader. The study will evaluate diagnostic performance, reader agreement, image quality, protocol adherence, reporting completeness, and consistency across participating centers and MRI vendors. Lymph-node staging and nodal treatment response are outside the research scope.

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