PET in the diagnosis of neuroendocrine tumors
2004 (English)In: Annals of the New York Academy of Sciences, ISSN 0077-8923, E-ISSN 1749-6632, Vol. 1014, 246-257 p.Article in journal (Refereed) Published
For general oncological imaging, positron emission tomography (PET) using [18F]fluoro-deoxy-glucose (FDG) has evolved as a powerful functional imaging modality. Unfortunately, FDG-PET has not been as advantageous for imaging gastropancreatic neuroendocrine tumors, and only tumors with high proliferative activity and low differentiation have shown an increased FDG uptake. Therefore, the 11C-labeled amine precursors L-dihydroxyphenylalanine and 5-hydroxy-L-tryptophan (5-HTP) were developed for PET imaging of these tumors. Because of the higher tumor uptake of the latter tracer in a study of patients with endocrine pancreatic tumors, 11C-5-HTP was chosen for further evaluation. In comparative studies of patients with carcinoids and endocrine pancreatic tumors, 5-HTP-PET proved better than CT and somatostatin receptor scintigraphy for tumor visualization, and many small, previously overlooked lesions were diagnosed by 11C-5-HTP-PET. The strong correlation found during medical treatment between the changes in the transport rate constant at repeated PET and those of U-HIAA indicates the possible use of 11C-5-HTP-PET also for therapy monitoring. By premedication of patients with Carbidopa orally before PET examination, in order to block the aromatic amino acid decarboxylase enzyme, the decarboxylation rate of 11C-5-HTP was decreased, leading to a higher tumor uptake and a considerably lower urinary radioactivity concentration.
Place, publisher, year, edition, pages
2004. Vol. 1014, 246-257 p.
Carcinoid Tumor/*radionuclide imaging, Humans, Neuroendocrine Tumors/*radionuclide imaging, Pancreatic Neoplasms/*radionuclide imaging, Tomography; Emission-Computed/*methods
IdentifiersURN: urn:nbn:se:uu:diva-73083DOI: 10.1196/annals.1294.027PubMedID: 15153441OAI: oai:DiVA.org:uu-73083DiVA: diva2:100994