The aim of this phase I-II study is to evaluate the efficacy and toxicity of PRRT with 177Lu-DOTATATE (Lu-PRRT) associated to metronomic chemotherapy with Capecitabine in patients affected by aggressive FDG-positive gastro-entero-pancreatic NET. Moreover to analyze the effects of the capecitabine metronomic schedule on the level of circulating angiogenetic factors.