Efficacy of Intensity Modulated Radiation Therapy After Surgery in Early Stage of Esophageal Carcinoma; (IMRT)

• Disease-free survival time [ Time Frame: up to 3 years ] [ Designated as safety issue: Yes ]
  including survival time from randomization to locoregional recurrence and to distal metastasis
  
  

• overall survival time [ Time Frame: up to 5 years ] [ Designated as safety issue: No ]
  survival time from randomization to death
  
  

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.