This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Esophagus, Subject name: Surgery
A patient with carcinoma lower 1/3 of oesophagus, receives chemo Radiotherapy and dysphagia shows complete response. What is the next step in management? 
Select and explain. 
A. Reassure, B. Follow with CT scan every 6 months, C. Esophagectomy, D. EUS to look for residual disease
C: Esophagectomy
Answer: C: Esophagectomy 
Explanation: - Clinical trials and meta-analyses have shown that a C + surgery regimen could significantly improve the survival of locally advanced esophageal carcinoma patients compared to surgery alone - Endoscopic biopsy, endoscopic ultrasonography, MRI (at various sequences) and PET-CT all had shocomings for evaluating cCR and the therapeutic effect of cCR (concurrent chemoradiation) and nC (Neoadjuvant chemoradiation therapy)