Endoscopic ultrasound-guided radiofrequency ablation of unresectable pancreatic cancer with low ablation power and multiple applications: a preliminary study of 11 patients.

Background Endoscopic ultrasound (EUS)-guided radiofrequency ablation (RFA) is a novel modality in the treatment of solid tumours. The aim of the study is to evaluate the technical feasibility, safety and efficacy of multiple-round EUS-RFA with low ablation power for unresectable pancreatic cancer. Methods We conducted a retrospective analysis of eleven cases with unresectable pancreatic cancer who underwent EUS-RFA between November 2013 and November 2018. For each lesion, RITA 1500X radiofrequency generator was used to deliver 5-10 watts ablation power for 90 seconds, repeatedly. Eight cases underwent the same procedure one week later. Additionally, one patient with the lesion size of 29.7 mm underwent 8 total sessions of RFA every other week. Results The procedure was successful in all cases and no major adverse events were observed. The post procedure imaging studies and serum CA19-9 level were performed 1 month after procedure, showing two patients had decreased lesion sizes and five patients had decreased serum CA19-9 level. Follow-up duration ranged 2 to 12 months. The patient who underwent 8 total sessions of RFA survived 12 months after followup and showed increased tumour apparent diffusion coefficient (ADC) value and 20% ablated area inside the tumour. Conclusions A multiple-round ablation with optimal RFA energy could be a technically feasible, safe and short-term efficacy option for those patients with unresectable pancreatic cancer.