<s>[INST] context: Carcinoma of the head of the pancreas is treated with radical excision of the head of the pancreas along with the duodenum. Continuity of the biliary and GI tract is established by performing hepaticojejunostomy, pancreaticojejunostomy, and gastrojejunostomy (Figure below). The 5-year survival rate is higher for periampullary carcinoma (30%) than that for pancreatic head lesions (10%). Most centers do not give irradiation routinely before or after surgery, because pancreatic cancers do not respond well to radiotherapy. Endoscopically placed stents alone are used only in palliative circumstances in patients with limited life expectancy.Pancreaticoduodenectomy (Whipple procedure). A: Preoperative anatomic relationships showing a tumor in the head of the pancreas. B: Postoperative reconstruction showing pancreatic, biliary, and gastric anastomoses. A cholecystectomy and bilateral truncal vagotomy are also part of the procedure. In many cases, the distal stomach and pylorus can be preserved, and vagotomy is then unnecessary [/INST] question: A 66-year-old man with obstructive jaundice is found on ERCP to have periampullary carcinoma. He is otherwise in excellent physical shape and there is no evidence of metastasis. What is the most appropriate treatment? | options: A: Radical excision (Whipple procedure) where possible B: Local excision and radiotherapy C: External radiotherapy D: Internal radiation seeds via catheter | answer: A </s>