Objective: Gallium (Ga)-68 DOTA-TATE positron emission tomography/computed tomography (PET/CT) is successfully used for imaging gastroenteropancreatic-neuroendocrine tumors (GEP-NET) and guiding treatment management especially in cases with heterogeneous morphology. This study investigates the effect of DOTA-TATE PET/CT on therapy management in GEP-NET.

Methods: Sixty-nine patients (29 women, 40 men) with well-differentiated GEP-NET were referred to our department for Ga-68-DOTA-TATE PET/CT scan analyzed retrospectively. Patients were scanned for staging (n=18), re-staging (n=36) and evaluation for treatment response (n=15). Treatment decisions were blindly correlated before and after PET/CT scan.

Results: The mean age was 56.63±13.03 (27-79) years. Patients had grade 1 (n=38) grade 2 (n=24) and grade 3 (n=7) tumors. More than half of the patients (53%) had positive findings for primary tumor and/or metastases. Thirteen patients with grade 2; 18 patients with grade 1; 6 patients with grade 3 tumors had positive findings with PET/CT scan. Primary tumors were in the pancreas, stomach, small bowel, appendix and colon. Additionally, metastases in liver, bone, lung, regional and distant lymph nodes were detected. Nineteen of 69 patients (27.5%) had a change in their treatment protocol. The highest change rate was detected at the group with grade 3 tumors.

Conclusion: Ga-68-DOTA-TATE PET/CT was shown as a successful method for imaging and guiding management of GEP-NET. The highest benefit in the treatment plan has been shown in patients with grade 3 tumors and group in the follow-up. Patients with a positive scan were also evaluated for peptide receptor radionuclide therapy as an alternative treatment.