This multicenter, prospective observational cohort study has the potential to optimize individualized chemoradiotherapy regimen for early-stage esophageal cancer patients who have received endoscopic submucosal dissection.

Our study can further improve the local-regional lymph nodes control rate and alleviate the toxicity of chemoradiotherapy.

Inclusion Criteria:

• 1. Esophageal cancer patients who are pathologically confirmed as pT1a-MM stage or pT1b stage after endoscopic submucosal dissection； 2. No definite contraindications for chemo-radiotherapy； 3. Informed consent has been signed； 4. Refused surgery after endoscopic submucosal dissection.

Exclusion Criteria:

• 1. Severe heart, brain, lung disease or renal dysfunction; 2. Previous history of other malignancies; 3. Prior radiation or chemotherapy 4. Researchers consider it inappropriate to participate in this experiment

Esophageal cancer patients, and pathologic-comfirmed pT1a-MM stage or pT1b stage