Here is the design of a clinical trial:

Official Title: Effects of Preoperative Enteral Immunonutrition for Esophageal Cancer Patients Given Neoadjuvant Chemoradiotherapy

Included conditions:
- Esophageal Neoplasms

Study Armgroups:
- {'label': 'Interventional group', 'type': 'EXPERIMENTAL', 'description': 'Patients receive omega-3 fatty-acid enriched enteral nutritional emulsion during the neoadjuvant chemoradiotherapy. Patients are meanwhile encouraged to intake 25-30kcal/kg through regular food.', 'interventionNames': ['Dietary Supplement: Preoperative immunonutrition']}
- {'label': 'Control group', 'type': 'NO_INTERVENTION', 'description': 'Patients are encouraged to intake 25-30kcal/kg through regular food without supplemental nutritional support before esophagectomy.'}

Interventions:
- {'type': 'DIETARY_SUPPLEMENT', 'name': 'Preoperative immunonutrition', 'description': 'Preoperative immunonutrition includes an omega-3 fatty-acid enriched enteral nutritional emulsion given by oral intake, nasogastric feeding tube or jejunostomy 600ml per day, lasting for the whole period of neoadjuvant chemoradiation. Meanwhile, oral intake is encouraged to reach 25-30kcal/kg through regular food.', 'armGroupLabels': ['Interventional group']}

Primary Outcomes:
- {'measure': 'Rate of postoperative nutrition and immune-related complications', 'description': 'Rate of gastrointestinal complications (anastomotic leakage, gastrointestinal dysfunction), metabolic complications (electrolyte disturbances, liver or renal dysfunction) and infectious complications(wound infection, catheter-related infection, pneumonia, sepsis, or other infections requiring antibiotics).', 'timeFrame': 'Up to 30 days after surgery'}

Please estimate the sample size based on the assumption: 
A bilateral significance level (α) of 0.05, a power of test (1-β) of 0.80, and an estimated drop rate of 15%.
Power and sample size calculation
        The power and sample size calculation was based on the hypothesis that pre-operative immunonutrition during the neoadjuvant therapy can reduce postoperative nutrition and immune-related complications after esophagectomy. According to the previously published articles [22] and our own experience, the related complication rates were estimated at 50% in the control group and 30% in the interventional group. The required sample size of interventional and control arm (ratioâ=â2:1) was therefore calculated as 137 cases and 69 cases to detect the reduction in related complications from 50 to 30% based on a bilateral significance level (Î±) of 0.05 and a power of test (1-Î²) of 0.80. Considering an estimated drop rate of 15%, the minimum sample size of this study is 244 patients, 162 cases in the interventional group and 82 in the control group.
        All the esophageal cancer patients in the outpatient and inpatient service are screened for eligibility. Recruiting announcements are also published on the website of the participating center to promote recruitment.