Esophageal cancer is one of the ten most common neoplasms worldwide. The histology is divided into squamous cell carcinoma and adenocarcinoma, and the criteria for staging are developed by the American Cancer Society (AJCC) based on tumor, lymph nodes, and distant metastases (TNM). Accurate staging evaluation methods include esophagogastroduodenoscopy (EGD), barium meal imaging, CT scans of the chest, abdomen and pelvis, and pathological biopsy of suspected distant metastases. In recent years, PET-CT can not only help to stage but also monitor the efficacy of esophageal cancer treatment and detect abnormal metastases earlier. Surgical resection is the gold standard of resectable esophageal cancer treatment. However, the clinical outcomes of surgery alone have been very disappointing. Therefore, after conducting a series of clinical trials to evaluate the efficacy of chemotherapy and radiotherapy, researchers concluded that: preoperative radiotherapy followed by surgery is the ideal common treatment modality for patients with resectable esophageal cancer; concurrent radiotherapy is an appropriate option for patients with unresectable advanced esophageal cancer; and radical concurrent radiotherapy is an appropriate option for patients with resectable esophageal cancer who are generally unsuitable for surgery. PET-CT is more accurate than conventional imaging methods in detecting metastases. Conventional imaging examinations diagnosing resectable esophageal cancer reveal metastases in distant lymph nodes and organs in 20% of them by PET-CT, and by PET-CT images showing areas of increased active FDG uptake, or painless small nodes, metastatic lesions and distant metastases in rarely seen anatomical sites of tumor, including skeletal muscle, brain, peritoneum, subcutaneous soft tissue, pleura, the PET-CT had a sensitivity of 100%, specificity of 55%, and positive and negative predictive values of 72% and 100%, respectively, for detecting therapeutic response.