Microwave ablation in locally advanced pancreatic carcinoma--a new look

Pancreatic carcinoma is by far the most common malignancy and is the 5th most lethal cancer in the world and 40% of these carcinomas are locally advanced and unresectable at the time of presentation. Palliative surgery and chemoradiotherapy have not produced significant improvement in survival. The overall prognosis of these pancreatic cancers is poor, if left untreated without any form of palliation. Out of many palliative methods adopted for such locally advanced pancreatic carcinoma, none has shown much survival benefit. Microwave ablation is a well established and safe local ablative method for liver tumors and microwave ablation for locally advanced pancreatic tumors has been extensively used around the world. This is our largest series of microwave ablation in 15 patients with locally advanced pancreatic head carcinoma. The aim of this study was to evaluate the safety, efficacy, feasibility and complications of microwave ablation in unresectable locally advanced pancreatic carcinoma.

In total, 15 patients, from January 2004 to December 2006, were included in this study all having locally advanced pancreatic tumors which were found to be unresectable on radiological evaluation. The 15 patients (10 male and 5 female) with a mean age of 67 years were subjected to open microwave ablation after laparotomy and additional palliative procedure like biliary bypass (end-to-side hepaticojejunostomy) and gastric obstruction bypass by antecolic gastrojejunostomy was performed in 6 patients. The location of tumor was predominantly in the head and/or uncinate portion of the pancreas (n=12) and head and body (n=3). The average size of tumor was 6cm (range 4-8cm) and almost all had major regional vascular invasion on CT or MR angiogram. All tumors were histologically proven before the procedure by core needle and frozen section biopsy. Patients with distant metastasis were not included in this study.

In all 15 patients, partial necrosis was achieved. There was no major procedure-related morbidity or mortality. Minor complications were seen in 6 out of 15 patients, mild pancreatitis (2), asymptomatic hyperamylasia (2), pancreatic ascites (1), and minor bleeding (1). All patients had close follow-up and the longest surviving patient had a follow-up of 22 months.

Microwave ablation is a beneficial therapy as a local effective procedure which is feasible and safe with acceptable minor complications in a locally advanced pancreatic tumor which can be used as part of a palliative or multimodality treatment, however, further long-term and properly designed studies are required to prove its usefulness in achieving survival benefit.