Radiofrequency ablation for locally advanced cancer of the pancreas.

Radiofrequency ablation (RFA) for locally advanced cancer of the pancreas appears an attractive proposition. Many Hepatobiliary Surgical Units currently have the equipment and technical expertise for ablation of non-resectable liver tumours and as RFA becomes established in this setting [1], so the concept of thermal ablation for non-resectable tumours is increasingly an accepted component of hepatobiliary practice. In any given cohort of patients with pancreatic cancer, only a minority are suitable for surgical resection [2, 3]. These individuals with operable disease should undergo surgical resection. An appreciable proportion will be unsuitable for any form of surgical therapy either because of co-morbidity or extent of disease but a small subset will have locally advanced, unresectable cancer without evidence of major co-morbidity or metastatic disease. It is this cohort for whom there is a consideration for the use of RFA. However, there are critical differences between the role of RFA in non-resectable lesions of the liver and a parallel application in pancreatic cancer. These can be considered in three categories: anatomical considerations, factors relating to the tumour biology of pancreas cancer and those relating to the physical properties of pancreatic parenchyma. First, anatomical considerations: liver tumours are surrounded by areas of normal hepatic parenchyma and extension of the zone of ablation beyond the tumour will usually not have adverse consequences. In contrast, lesions in the head of the pancreas will be traversed by the distal common bile duct and be closely related to the duodenum, stomach, transverse colon and portal vein-the risks of inadvertent thermal injury are considerable and made more dangerous when understood in the context of an un-resectable tumour. In this setting, inadvertent thermal necrosis of the duodenum cannot then be retrieved by resection. The second group of considerations relate to tumour biology: hepatic metastases are usually discrete lesions whereas locally advanced pancreatic cancer can be physically diffuse and encase the superior mesenteric artery, extend retroperitoneally or proximally rendering direct ablation of all tumour bulk impractical. The third group of considerations relate to the efficacy of thermal ablation of pancreatic parenchyma. Given the dearth of available information in this area, our group established and validated an ex-vivo porcine model of radiofrequency ablation of the pancreas [4]. In this model, we were able to demonstrate a reproducible, temperature-dependent ablation. As haematoxylin and eosin preparations are inadequate for assessment of ablation, we used the method described by Scudamore [5] relying on loss …