Therapy of Pancreatic Neuroendocrine Tumors: Fine Needle Intervention including Ethanol and Radiofrequency Ablation

Abstract

Pancreatic neuroendocrine tumors (PNETs) are increasingly being detected, though usually as incidental findings. Majority of the PNETs are non-functional and surgical resection is the standard of care for most of them. However, in patients with small PNETs localized within the pancreas, who are unfit or unwilling for surgery, alternate methods of treatment are needed. Direct methods of ablation of PNETs, using either ethanol injection or radiofrequency ablation (RFA), are emerging as effective methods. The limited literature available as case reports or case series on endoscopic ultrasound (EUS)-guided local ablation using either ethanol or RFA has demonstrated safety and efficacy along with short- to medium-term sustained relief. Long-term benefits with these local ablative therapies are awaited. Comparative studies are needed to show which of these two competing technologies is superior. Finally, comparative trials of EUS-guided ablation with surgical resection in terms of efficacy and safety will ensure their place in the management algorithm.

Efficacy and safety of scheduled early endoscopic ultrasonography‐guided ethanol reinjection for patients with pancreatic neuroendocrine tumors: Prospective pilot study

“…Previous reports on treatment with EUS-guided ethanol injection have described the amount of ethanol as ranging from 0.3 to 8.0 mL. [3][4][5][6][7] Park et al 3 reported the outcomes of 11 patients with 14 tumors, and a median 1.6 (range: 0.5-3.8) mL of ethanol per session was used for tumors of a median 12.2 (range 8-19) mm in size. Median total amount of ethanol for each tumor was thus 2.5 (range 0.5-7) mL.…”

“…The optimal approach for treating patients with nonfunctional, small (≤2 cm in diameter) pancreatic neuroendocrine tumors (p‐NET) is controversial . Recently, endoscopic ultrasonography (EUS)‐guided ablation has been proposed for the treatment of patients with small p‐NET . Using a pure ethanol or ethanol‐lipiodol emulsion, the complete ablation rate has been reported to be approximately 50% with a single session and up to 60% with an additional session .…”

“…Using a pure ethanol or ethanol‐lipiodol emulsion, the complete ablation rate has been reported to be approximately 50% with a single session and up to 60% with an additional session . Mild pancreatitis occurred in a few patients who required injection with a large amount of ethanol in one session …”

“…1,2 Recently, endoscopic ultrasonography (EUS)-guided ablation has been proposed for the treatment of patients with small p-NET. [3][4][5][6][7][8] Using a pure ethanol or ethanol-lipiodol emulsion, the complete ablation rate has been reported to be approximately 50% with a single session and up to 60% with an additional session. 3,4 Mild pancreatitis occurred in a few patients who required injection with a large amount of ethanol in one session.…”

“…3,4 Mild pancreatitis occurred in a few patients who required injection with a large amount of ethanol in one session. [3][4][5][6][7] When an additional session is scheduled before the first injection, the volume of ethanol can be adjusted to be within the safe range. Therefore, we launched the current trial to assess whether or not scheduled early EUS-guided ethanol reinjection is effective and safe for treating small p-NET.…”