[Radiofrequency ablation of pancreatic neuroendocrine tumor]

Pancreatic neuroendocrine tumors (PNETs) include a broad range of neoplasms spanning from relatively benign to malignant. Radical resection has been advocated as the only curative method. Debulking (R2) resection can be indicated for locally unresectable PNETs. Debulking surgery improves the quality of life and prolongs overall survival. The disadvantages of this approach include bleeding, pancreatic fistula and tumor spread. No alternative method that would eliminate these complications has been published yet. Considering the encouraging results of the studies describing radiofrequency ablation (RFA) of locally advanced pancreatic cancer, a question arises, whether it might be possible to use RFA as a R2 resection alternative in PNETs.

A 73-year-old gentleman had been admitted due to abdominal pain and hyperglycaemic syndrome. Contrast-enhanced CT showed a tumor of pancreatic head invading portal vein (PV) and superior mesenteric vein (VMS). A surgery was indicated on the basis of EUS-guided FNAB that verified a PNET of uncertain biological behaviour. The surgery confirmed a locally advanced tumor of pancreatic head invading the PV and SMV. Due to the polymorbidity, radical pancreatoduodenectomy with SMV resection was not indicated. Because of the presence of symptoms, RFA of the PNET using ValleyLab generator with cooltip cluster electrode, was performed. Postoperative course was uneventful. Final immunohistochemical examination verified a well-differentiated grade 1 PNET. The patient was regularly monitored during a three-year follow-up. The quality of life was evaluated using standardized EORT QLQ-30 questionnaire. Pain was assessed by a ten-point visual analogue scale (VAS). Ablated area was evaluated annually by contrast-enhanced CT. Postoperatively, abdominal pain ceased (pain decrease from 2 to 0 on VAS). Insulin dose was reduced from 46 IU (international units) to 20 IU of Humulin-R per day. CT verified tumor regression according to RECIST (response evaluation criteria in solid tumors). During the three-year follow-up, no local progression or tumor dissemination was observed.

We present the first case report of a patient with locally advanced symptomatic pancreatic neuroendocrine tumor successfully treated by intraoperative radiofrequency ablation. More clinical studies are needed to evaluate the clinical relevance of this cytoreductive method in the PNET indication.