The purpose of this study is to determine the efficacy of preventive intensity modulated radiation therapy after surgery in stage T2-3N0M0 disease of thoracic esophageal squamous cell carcinoma(UICC 7th edition) and to identify the subgroup benefiting from the treatment.

Although preoperative chemoradiation therapy followed by surgery is the most common approach for patients with resectable esophageal cancer, the considerable number of esophageal cancer patients received operation as the first treatment modality. Accordingly, postoperative treatments have been playing an important role because of the poor survival rates of the patients who have been treated with resection alone. The existing data shows that the 5-yeal survival rate of stage T2-3N0M0(UICC 7th edition) of thoracic esophageal squamous cell carcinoma(TESCC) after surgery is about 50% ,and locoregional lymph nodes metastases is responsible for the main cause of failure while distal metastases account for relatively less ratio. Therefore, the subclinical residual tumor is affirmative even if the early disease has been undergone curable excision and local adjuvant treatment may be essential. While we have proved the value of prophylactic radiation therapy after radical esophagectomy for esophageal carcinoma with positive lymph node metastases and stage Ⅲ disease, there is still lack of clear evidence for prophylactic radiation therapy in stage T2-3N0M0 disease now. The comparison of conventional 2-dimensional radiotherapy after operation versus surgery alone does not show statistically significant difference for stage T2-3N0M0 disease in our previous report. In the precise radiotherapy setting, more and more evidences of non-randomised control study indicate the trend or preliminary results of dosimetric advantages of IMRT translating into substantive benefits in both survival and locoregional control compared with 3- dimensional conformal and 2-dimensional conventional radiotherapy for the treatment of esophageal carcinoma, but it remains to be confirmed in the randomized control study that whether the IMRT is effective to improve the clinical outcomes of stage T2-3N0M0 patients of TESCC. In view of this, we designed the randomized controlled trial to determine the clinical efficacy and toxicity of prophylactic IMRT after surgery in stage T2-3N0M0 disease of TESCC.

Inclusion Criteria:

• Stage T2-3N0M0 disease of TESCC patients confirmed by pathology studies who received R0 operations in Cancer Institute & Hospital，CAMS；
• KPS≥70 before radiotherapy;
• Did not receive neoadjuvant or adjuvant treatment;
• No clear recurrent or metastatic lesions before radiotherapy;
• Intensity modulated radiation therapy(IMRT) is accepted;
• Regular follow-up.

Exclusion Criteria:

• Exploratory thoracotomy or palliative surgery;
• No clear recurrent or metastatic sites;
• Recurrence or metastasis is not certain;
• death of no definite cause.
• Irregular follow-up;