Neuroendocrine tumours (NET) have a particular tendency to express functional receptors and/or uptake mechanisms. Radionuclides, such as 111 In-pentetreotide, a somatostatin analogue, which bind to somatostatin receptors, present an imaging modality that has been used for both the diagnosis and staging of NET. Scintigraphy with 111 In-pentetreotide can identify lesions beyond the diagnostic sensitivity of conventional imaging modalities. In addition, NET that demonstrate positive uptake to a diagnostic 111In-pentetreotide can, in theory, be treated with these radionuclides, thus presenting a novel and evolving therapeutic modality in addition to other traditional therapeutic approaches.