SPECT/CT in neuroendocrine tumours

Abstract

Neuroendocrine tumours (NETs) are a heterogeneous group of neoplasms with very varying clinical expressions. Nuclear medicine plays an important role in the imaging and treatment of these tumours. Despite the advent of several PET radiopharmaceuticals, SPECT imaging with the labelled somatostatin receptor analogue In-111 pentetreotide or with radioiodinated MIBG is still a very useful technique for evaluating patients with NETs. The aim of this review is to summarise the applications, in the study of NETs, of hybrid SPECT/CT imaging performed using these gamma-emitting radiopharmaceuticals. The combined use of SPECT and CT in hybrid devices is of value when applied to scintigraphic procedures in NETs: the addition of anatomical maps provides a precise localisation of SPECT findings and allows the exclusion of disease in sites of physiological tracer uptake. These advantages translate into better sensitivity and specificity, both of which are essential for the diagnosis and accurate staging of NETs. SPECT/CT hybrid images are able to provide additional information that improves the diagnostic accuracy and confidence of SPECT interpretation and leads to changes in therapeutic options in about 25 % of patients. Therefore, SPECT/CT should be routinely performed and considered standard practice in the diagnostic work-up and treatment planning of patients with NETs submitted to In-111 pentetreotide or radioiodinated MIBG imaging. This approach can still be used as an alternative to PET/CT options when the latter are not available.