Endocrine Abstracts

A multidisciplinary team is responsible for the management of over 1,200 NET patients per year in our hospital. Tumor board decisions for peptide receptor radiotherapy (PRRT) are based on the Bad Berka Score which takes into account molecular imaging features and clinical aspects. The therapy plan for each patient is individualized. Retrospective analysis was performed in 1048 patients (age 4–85 years) with progressive NETs treated at our center since 2004 using Lu-177 (n=331), Y-90 (n=170) or both (n=499). Follow up was up to 132 months. G1-2- NETs accounted for 54%. The median overall survival (OS) of all patients from start of PRRT was 52 months. A phase III multicentric, randomized, controlled trial (NETTER-1) has evaluated 177Lu-DOTA0-Tyr3-Octreotate (Lutathera^®) in patients with progressive, somatostatin receptor positive midgut NETs. The primary endpoint was PFS per RECIST 1.1 criteria. Secondary objectives included objective response rate, overall survival, toxicity, and quality of life. Enrolment was completed in Feb-2015 (230 patients in 35 European and 15 US sites). The number of centrally confirmed disease progressions or deaths was 23 in the Lutathera group and 67 in the Octreotide LAR 60 mg group. The median PFS was not reached for Lutathera and was 8.4 months with 60 mg Octreotide LAR (95% CI: 5.8–11.0 months), P<0.0001, with a hazard ratio of 0.21 (95% CI: 0.13–0.34). Although data are not mature enough (13 deaths in the Lutathera and 22 in the LAR group), an improvement in OS appears very likely. PRRT lends a significant benefit in PFS (and presumably in OS). The combination of Lu-177 and Y-90 may be more effective than either radionuclide alone. Up to 10 cycles of PRRT, given over several years were tolerated very well by most patients. Severe renal toxicity can be avoided, myelotoxicity is usually mild. MDS occurs in approx. 3% of all patients treated. Quality of life can be significantly improved. PRRT may be effectively combined with TACE, SIRT, radiofrequency ablation (RFA), chemotherapy (e.g. using Capecitabine, Temozolomide), and kinase inhibitors. PRRT should be performed only at specialized centers as NET patients need highly individualized interdisciplinary treatment and long term care.