Clinical and radiological criteria for candidate patients with small bowel neuroendocrine neoplasms (SB-NEN) for minimally invasive surgery: A single-centre experience

e16246 Background: Although open resection represents the standard of care of localized small bowel neuroendocrine neoplasms (SB-NEN), minimally invasive surgery (MIS) has proven to be a viable alternative in patients with low disease burden. This study aims to assess the reliability of preoperative clinical and radiological criteria used at European Institute of Oncology (IEO) to candidate patients with SI-NEN to MIS. Methods: Patients diagnosed with SB-NEN and eligible for MIS at IEO were retrospectively evaluated between 2013 and 2022. Preoperative physical examination, CT enterography (CTE) and Ga68-DOTATOC-PET-CT were used for clinical staging. At IEO NEN multidisciplinary tumor board, the following eligibility criteria were adopted to candidate patients to MIS (curative or palliative): number and localization of primary tumor, grade of superior mesentery artery and vein encasement by lymph-node metastases of 0-2 according IEO criteria (based on Lardiere-Degalte classification). Information on morphology and carcinoid syndrome were collected. The primary endpoint was laparotomy conversion rate. Results: Twelve patients were selected. Patients’ characteristics are available. Median age at surgery was 55 years (range: 33–73). Among these patients, based on pathological findings, 8 (67%) had confirmed nodal involvement, 3 (25%) metastatic disease and 4 (33%) multifocal primary tumor. Vascular involvement (based on IEO criteria) was found in 9 patients (75%). Of note, only 3 (25%) patients had a functioning tumor as a preoperative finding and all tumors resulted well-differentiated. Among 12 patients which underwent laparoscopic surgery, none has been converted to laparotomy surgery. After a median follow-up of 25.3 months (range: 2.5-71.3), the 1-year disease free survival for non-metastatic patients was of 100%. Conclusions: the assessment of tumor burden with 68 Ga-PET-CT and CTE according to IEO criteria could be a reliable method to candidate patients affected by SB-NEN to MIS, according to a multidisciplinary approach.[Table: see text]