SUN-329 177Lu-DOTA-TATE Treatment in Patients with Well-Differentiated Pancreatic Neuroendocrine Tumors: A Single-Center 7-Year Experience

Introduction: Pancreatic neuroendocrine tumors (PNETs) frequently express somatostatin receptors on their cell membranes. These receptors are targets for therapy with Lutetium-177-labeled somatostatin analogs. Peptide receptor radionuclide therapy (PRRT) with 177Lu-DOTA-TATE is a therapeutic option in patients with disease progression during first-line somatostatin analogue therapy. The aim of this study was to evaluate the efficacy and side-effect profile of this treatment in adult patients with well differentiated PNETs. Material and Methods: A retrospective study was conducted on a cohort of adult patients with well differentiated PNETs who received at least 3 cycles of treatment with 177Lu-DOTA-TATE, between April 2011 and January 2018. Results: Among 31 patients reviewed, 27 (87.1%) completed all 3 cycles of 177Lu-DOTA-TATE. This group of patients had a median age of 52.6 years old. The median follow-up time since the first cycle of treatment was 27.8 months and the median dose used in these 3 cycles was 19.61 GBq. Twenty patients (74.1%) had been previously submitted to resection of the primary tumor. All patients had metastatic disease. The most frequent locations of the metastasis were in the liver [23 (85.2%)] and in lymph nodes [17 (63.0%)]. Nine patients (28.1%) felt acute side effects in at least one treatment cycle and nausea was the most frequent symptom [occurred in 8 patients (25.8%)]. Symptomatic improvement happened in 13 (48.1%) of 15 previously symptomatic patients [11 patients (40.7%) were asymptomatic previous to the treatment]. Partial imagiological response occurred in 15 (55.6%) patients. The median time of imagiological progression was 18.9 months since the first cycle of treatment. During the follow-up 10 (37.0%) patients died. The median survival time was 21.8 months. Conclusion: Peptide receptor radionuclide therapy with 177Lu-DOTA-TATE is an effective and well-tolerated treatment in patients with differentiated PNETs, making this a suitable treatment for patients with inoperable/metastatic disease.