Esophageal cancer (EC) is the seventh most frequently diagnosed cancers and the sixth leading causes of cancer death worldwide . It is one of the most common malignancy in China, with the third highest morbidity and mortality rate. More than 90% of patients with EC in China have esophageal squamous cell carcinoma (ESCC). Neoadjuvant chemoradiotherapy (nCRT) followed by surgery is currently widely used strategy for locally advanced surgical EC.

At present, conventional imaging methods have certain defects (focus only on the volume change) in the evaluation of the efficacy of nCRT. Whereas functional imaging can more comprehensively reflect the biological and microstructural characterization of tumors. The changes of these aspects of tumors can be observed earlier than volumetric changes of tumors.

The normal metabolism of the body is the basis for ensuring life activities. Due to the increased energy demand and proliferation of tumor tissue in patients with cancer, the metabolism of patients is different from that of normal person. Thus, the metabolic alterations seen in cancer cells have emerged as one of the hallmarks of cancer. Previous metabolomic studies have demonstrated various metabolic alterations in patients with ESCC. Many metabolites have been found to be promising diagnostic, staging or prognostic biomarkers for ESCC. However, there are few studies on metabolic markers on the chemoradiation sensitivity of esophageal cancer.

Therefore, the aim of the present study is to evaluate the value of functional imaging parameters and metabolic markers in assessing and predicting pathological response in patients who underwent nCRT for ESCC.

Inclusion Criteria:

• Pathologically confirmed esophageal squamous cell carcinoma；
• AJCC 7th edition staging T3-T4a or N+；
• No radiotherapy or chemotherapy in the past；
• 18-75 years old；
• Hematology, biochemical and organ function indicators meet the following requirements: 1) White blood cells ≥ 3.0 x109/ L; 2)neutrophil cells ≥ 1.5 x109/ L; 3) Platelet count ≥85 x109/L; 4) Hemoglobin ≥90 g/L; 5) Total bilirubin ≤1.5 times normal value; 6) ALT≤ 1.5 x normal value; AST ≤1.5 times the normal value; 7) Serum creatinine ≤1.5 times the normal value, and creatinine clearance rate (Ccr) ≥60ml/min (Cockcroft-Gault);
• ECOG score 0-1 points;
• Able to eat a semi-liquid diet；
• sign an informed consent.

Exclusion Criteria:

• Have received radiotherapy or systemic chemotherapy;
• During pregnancy or lactation;
• Uncontrollable serious medical diseases;
• Unable to sign informed consent;
• With distant metastasis;
• Suffering from the second type of malignant tumor (except skin squamous cell carcinoma and carcinoma in situ of other organs) within the past 5 years；
• Those who cannot receive MRI examination;
• Chemotherapy drugs or contrast agents Allergic.

Patients with resectable esophageal or gastroesophageal squamous cell carcinoma, scheduled to receive neoadjuvant chemoradiotherapy