Endoscopic ultrasound-guided Nd:YAG laser ablation of recurrent pancreatic neuroendocrine tumor: a promising revolution?

Endoscopic ultrasound (EUS) has developed from a diagnostic tool into a therapeutic one [1]. A 46-year-old woman was diagnosed with recurrent pancreatic neuroendocrine tumor (PNET) by positive 68Ga-[1, 4, 7, 10-tetraazacyclododecane1,4,7,10-tetraacetic acid]-1-NaI3-octreotide (68Ga-DOTA-NOC) positron emission tomography (PET) (●" Fig.1a). Two years earlier she had undergone curative distal pancreatectomy for previous PNET in the setting of multiple endocrine neoplasia type I. At computed tomography (CT) scan, the lesion appeared as a 9-mm nodular area with early contrast enhancement on the pancreatic residual body (●" Fig.2a). The patient refused total pancreatectomy. Laser ablation under EUS guidance was therefore performed using a neodymiumdoped yttrium aluminum garnet (Nd: YAG) laser, at 4.0W for 300 seconds (●" Fig.3). No complications occurred during the procedure. At CT immediately after laser ablation, the ablated lesion appeared as a well-defined 35-mm coagulative necrotics area (●" Fig.2b). Neither perilesional parenchymal alteration nor vascular damages were observed. The 2month follow-up CT scan showed the ablated area to be 18mm (●" Fig.4a); at 1 year the area was 9mm (●" Fig.4b), with no metabolic activity on 68Ga-DOTA-NOC PET (●" Fig.1b). Laser ablation is a minimally invasive method for destroying tumors within solid organs, and works by directing lowpower laser light energy into the tissue. It has been used for primary and secondary liver tumors [2–4]. The potential advantage of laser ablation over other laser-inFig.1 Pre-treatment 68Ga-DOTA-NOC positron emission tomography (PET) revealed a lesion in the residual pancreatic body with metabolic activity (arrow). 68Ga-DOTANOC PET 1 year after laser ablation (on the right), showed no metabolic activity in the pancreatic region.