Endoscopic ultrasound‐guided radiofrequency ablation for nonfunctional pancreatic neuroendocrine tumors: Put the gun away or keep shooting?

Abstract

We read with great interest the retrospective study by Marx et al. 1 reporting endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) treatment in 27 patients with sporadic, G1, nonfunctional pancreatic neuroendocrine tumors (NF-pNETs) (mean lesion size 14 AE 4.6 mm). There was a 93% complete response, with three cases of severe acute pancreatitis (11.1%), which evolved into a pancreatic fluid collection requiring EUS-guided drainage. These patients had lesion diameter of 10, 10, and 9 mm and an age ranging from 58 to 66. 1 Was performance of EUS-RFA indicated in these patients? The European Neuroendocrine Tumor Society guidelines recommends surveillance in patients with lesions <20 mm. However, the level of evidence beyond this conclusion is extremely low. 2 Conversely, in surgical series, about 30% of small NF-pNETs are operated, with serious adverse events (AEs) in 18-32% of cases. 3,4 EUS-RFA has been proposed as a minimally invasive alternative to surgery. When a new therapeutic modality is introduced, proper patient selection is critical in order to preserve your gun from a rapid and irreversible failure. In our opinion, this was not the case in the paper by Marx et al., 1 where grade III AEs ocurred in NF-pNETs ≤10 mm, which may never ever grow up and in which control of RFA current dispersion might be difficult, also if the smallest 5 mm needle was utilized, as we assume.A recent systematic review has reported 93% effectiveness and no major AEs (mean lesion size 16 mm). 5 If this is the case, we believe we should keep shooting EUS-RFA for small selected NF-pNETs, with size ranging from 14-15 to 20 mm, especially those located in the pancreatic head, while balancing other patient and lesion variables. 2 With this in mind, these patients should be offered EUS-RFA, surveillance and surgery to make them able to take their most appropriate personal decision.

Endoscopic ablation therapy for the pancreatic neoplasms

“…Further evaluations are needed to decide proper patient selection and needle tip size for small tumors. 47 Imperatore et al 48 conducted a systematic review of EUS-RFA for pancreatic NENs. Sixty-one patients with 73 tumors (mean size 16 mm; insulinomas 30.1%) were included in 12 studies.…”

“…The used needle tip size was 10 mm. Further evaluations are needed to decide proper patient selection and needle tip size for small tumors 47 . Imperatore et al 48 .…”