Inclusion Criteria:  Age of 20-85 years, with ECOG performance 0-2 Thoracic esophageal cancer with clinical stage I-III and biopsy proof. Complete first course CCRT with minimum doses of 40 Gy to tumor and nodal area via external beam radiotherapy (EBRT). Patient whose tumor is resectable but declined to receive surgery after first course CCRT.  Exclusion Criteria:  T4b tumor status (tracheal / bronchial mucosa, aortic involvement, or fistula formation). Stenosis of esophageal lumen that cannot be bypassed by the applicator. The primary tumor length exceeds 20cm. The patient is participating in other clinical trials.