Abstract
BACKGROUND AND AIMS: Pancreatic neuroendocrine tumors (PNETs) are rare and often diagnosed at advanced stages, limiting curative options. For PNETs <20 mm, endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) has emerged as a minimally invasive therapeutic alternative. This study investigates the role of magnetic resonance imaging (MRI) in monitoring postablation enhancement, emphasizing its utility in assessing treatment efficacy. METHODS: Four PNETs in the uncinate process, measuring <15 mm, underwent EUS-RFA (insulinomas [2 patients]; nonfunctioning PNETs [2 patients]). MRI was performed immediately (2 patients) and 30 days (2 patients) after EUS-RFA to confirm tumor destruction, with enhancement analysis as the main marker of effective ablation. RESULTS: The diagnostic confirmation of all PNETs was obtained through EUS fine-needle biopsy before EUS-RFA. One insulinoma required 2 sessions (25%), whereas the other 3 needed only 1 EUS-RFA session (75%). All 5 sessions were technically successful (100%) and clinically effective in 75% of cases after a single application. Mild duodenal bleeding was observed in case 4 (20%). MRI demonstrated complete destruction of the nodules in all cases. CONCLUSIONS: EUS-RFA is a safe, well-tolerated, and effective treatment for both functioning and nonfunctioning PNETs <20 mm. It offers a minimally invasive alternative for patients unfit for or unwilling to undergo surgery or active surveillance. MRI proved valuable in assessing postablation tumor vascular enhancement.