The proposed clinical trial will be a Phase II, open label, single site study in subjects with somatostatin receptor positive tumours. Radioactive Lu-DOTA-TATE doses are fixed within a range of 1.85 - 5.55 GBq ± 10%, with individual doses based on specified risk factors. There will be two groups of subjects enrolled in this study. Group A subjects (primary therapy) will have somatostatin receptor positive tumours and have never received Lu-DOTA-TATE. Group B subjects (maintenance therapy) will be those subjects who have previously received Lu-DOTA-TATE under the Special Access Programme (SAP) and will maintain their treatment schedule when they are entered into the study.