RADIONUCLIDE IMAGING AND THERAPY OF NEUROENDOCRINE TUMOURS

The incidence and prevalence of neuroendocrine tumours (NETs) are on the rise. Although NETs are a heterogeneous group of tumours, they have some similar properties, for example, that they can concentrate neuroamines and tend to have a high degree of somatostatin receptor (SSR) expression. These mechanisms can be exploited and this article discusses the important role of radionculide imaging and radionculide therapy in the management of NETs based on these mechanisms. This article reviews the current literature and discusses the role of radionuclide imaging in NETs both in terms of SSR imaging and neuroamine (metaiodobenzylguanidine [MIBG]) imaging. We discuss state-of- the-art 68Ga-radiopeptide imaging and indications for it use. We also discuss the role of 18F-FDG and other tracers in the management of NETs. The second half of the article focuses on radiotargeted treatment of NETs, discussing I-131 MIBG therapy and focussing on the emergence of peptide receptor radionuclide therapy. We discuss the clinical results, toxicities and patient selection for PRRT. Key words: DOTA octreotide, DOTATATE, Ga-68, Lu-177, metaiodobenzylguanidine, neuroendocrine tumours, peptide receptor radionuclide therapy, Y-90

Automated quantification with BRASS reduces equivocal reporting of DaTSCAN (123I-FP-CIT) SPECT studies

BACKGROUND: 123I-FP-CIT (DaTSCAN) SPECT studies of the nigrostriatal pathway are a valuable tool in the diagnosis of movement disorders. However some scans are reported as equivocal with potential adverse consequences. We investigated whether the use of quantification of tracer uptake within the striatum can be used to reduce the number of equivocal reports. MATERIAL AND METHODS: BRASS software (Hermes, Sweden) was used to quantify striatal tracer uptake in DaTSCAN studies of patients referred to our institution. Scans were quantified and numerical limits were determined to distinguish between normal and abnormal scans. Scans were then re-reported both with, and without, the use of quantification. Number of equivocal reports and accuracy of reporting between the two types of reporting were compared. RESULTS: Scan reporting using quantification led to a significant reduction in the number of equivocal reports with no significant change in reporting accuracy. CONCLUSION: Automated quantification of DaTSCAN studies with BRASS and the use of numerical limits can decrease the number of equivocal reports without affecting report accuracy.