Feasibility of Radio-Guided Surgery with ⁶⁸Gallium-DOTATATE in Patients with Gastro-Entero-Pancreatic Neuroendocrine Tumors.

BACKGROUND: Surgery is the only definitive therapy for gastro-entero-pancreatic neuroendocrine tumors (GEPNETs), and achieving complete tumor resection is an important prognostic factor. Radiopharmaceuticals such as (68)Ga-DOTA peptides have been developed that offer superior accuracy for localization of GEPNETs. The study aim was to determine the feasibility of radio-guided surgery (RGS) using (68)Ga-DOTATATE in patients with primary and recurrent GEPNETs.

METHODS: Fourteen patients with GEPNETs were enrolled onto a prospective study to determine the feasibility of RGS with (68)Ga-DOTATATE. Findings from preoperative imaging, intraoperative exploration, RGS, and pathology were analyzed.

RESULTS: The median decay corrected target count rate was 172.6 (range 28.15-2341) for tumors, with a tumor-to-background ratio (TBR) of 4.46 (range 1.6-43.56). The median lesion size was 1.55 (range 0.5-15) cm. There was no significant correlation between preoperative imaging maximum standardized uptake value (SUVmax) of the lesions and TBR (Spearman r = - 0.01, p = 0.9), TBR and tumor size (Spearman r = 0.29, p = 0.14), and SUVmax and tumor size (Spearman r = 0.22, p = 0.28). The probe showed correct identification for gastric and small intestine neuroendocrine tumor (NET), including lymph node metastasis in 17 (81.0 %) of 21 cases, with a median TBR of 3.5 (1.6-40.2). For pancreatic NETs and lymph node metastasis, 16 (66.7 %) of 24 were correctly identified by RGS.

CONCLUSIONS: Our study shows that RGS with (68)Ga-DOTATATE is feasible and correctly confirms bowel NETs and metastatic mesenteric lymph nodes. Further studies are needed to determine the benefit of RGS with (68)Ga-DOTATATE.