A multicenter, stratified, open, randomized, comparator-controlled, parallel-group phase III study. In this study, treatment with 177Lu-DOTA0-Tyr3-Octreotate plus best supportive care (30 mg Octreotide LAR) will be compared to treatment with high dose (60 mg) Octreotide LAR in patients with inoperable, somatostatin receptor positive, histologically proven midgut carcinoid tumours; these patients should be progressive under Octreotide LAR. In case patients in either arm experience clinical symptoms (i.e. diarrhoea and flushing) associated with their carcinoid tumours, Octreotide s.c. rescue injections are allowed.