Radiolabeled Somatostatin Analogues Therapy in Advanced Neuroendocrine Tumors: A Single Centre Experience

The aim of this study was to assess the efficacy of PRRT in patients with advanced neuroendocrine tumors (NETs). Patients and Methods. From January 2007 to August 2011, we enrolled 65 patients (m/f 38/27; mean age 65 years, range 33-83) with advanced NETs having enhanced SSTR expression, treated with PRRT. The enhanced expression of SSTR was assessed using (68)Ga-DOTATOC/DOTATATE PET/CT. Among all the enrolled patients, 6 of them were excluded from the present analysis since they voluntarily interrupted treatment. Mean activity/cycle of 2.6 GBq ((90)Y-DOTATOC/DOTATATE) or 6.0 GBq ((177)Lu-DOTATOC/DOTATATE) was administrated intravenously (max 9 cycles). Results. Complete response (CR) was found in 1/59 (2%) patients, partial remission (PR) in 24/59 (40.5%) patients, stable disease (SD) in 24/59 (40.5%), and progression (PD) in 10/59 (17%) patients. The overall tumor response rate (CR + PR) was 42.5%. In 40.5% of patients, the disease could be stabilized. Overall, 49 out of 59 patients had no tumor progression (83%). Twelve patients out of 59 (20%) had grade 2-3 hematological side effects including anemia, thrombocytopenia, and leukopenia. Long-term nephrotoxicity was observed in 3 patients (2 moderate, 1 severe). Conclusions. PRRT is a promising perspective for patients with advanced NETs.