title: Whole-body (11)C-5-hydroxytryptophan positron emission tomography as a universal imaging technique for neuroendocrine tumors: comparison with somatostatin receptor scintigraphy and computed tomography.
abstract: Neuroendocrine tumors (NETs) can be small and situated almost anywhere throughout the body. Our objective was to investigate whether whole-body (WB) positron emission tomography (PET) with (11)C-5-hydroxytryptophan (5-HTP) can be used as a universal imaging technique for NETs and to compare this technique with established imaging methods. Forty-two consecutive patients with evidence of NET and a detected lesion on any conventional imaging (six bronchial, two foregut, 16 midgut, and two thymic carcinoids; one ectopic Cushing's syndrome; four gastrinomas; one insulinoma; six nonfunctioning endocrine pancreatic tumors; one gastric carcinoid, one paraganglioma; and two endocrine-differentiated pancreatic carcinomas) were studied. The WB-(11)C-5-HTP-PET examinations were compared with WB-computed tomography (CT) and somatostatin receptor scintigraphy (SRS). Tumor lesions were imaged with PET in 95% of the patients. In 58% of the patients, PET could detect more lesions than SRS and CT and equal numbers in 34%, whereas in three cases, SRS or CT showed more lesions. In 84% (16 of 19 patients), PET could visualize the primary tumor compared with 47 and 42% for SRS and CT, respectively. The surgically removed PET-positive primary tumor sizes were 6-30 mm. To conclude, this study indicates that WB-(11)C-5-HTP-PET can be used as a universal imaging method for detection of NETs. This study also shows that WB-(11)C-HTP-PET is sensitive in imaging small NET lesions, such as primary tumors, and can in a majority of cases image significantly more tumor lesions than SRS and CT.
authors.affiliation: Department of Medical Sciences/Endocrine Oncology, Uppsala University Hospital, S-751 85 Uppsala, Sweden. hakan.orlefors@medsci.uu.se
authors.forename: H
authors.initials: H
authors.lastname: Orlefors
authors.forename: A
authors.initials: A
authors.lastname: Sundin
authors.forename: U
authors.initials: U
authors.lastname: Garske
authors.forename: C
authors.initials: C
authors.lastname: Juhlin
authors.forename: K
authors.initials: K
authors.lastname: Oberg
authors.forename: B
authors.initials: B
authors.lastname: Skogseid
authors.forename: B
authors.initials: B
authors.lastname: Langstrom
authors.forename: M
authors.initials: M
authors.lastname: Bergstrom
authors.forename: B
authors.initials: B
authors.lastname: Eriksson
mesh_terms: D006916:5-Hydroxytryptophan / Q000493:pharmacokinetics*; D002250:Carbon Radioisotopes; D005260:Female; D006801:Humans; D008297:Male; D018358:Neuroendocrine Tumors / Q000145:classification / Q000000981:diagnostic imaging*; D004369:Pentetic Acid; D049268:Positron-Emission Tomography / Q000379:methods; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed
chemical_list: D002250:Carbon Radioisotopes; D004369:Pentetic Acid; D006916:5-Hydroxytryptophan