title: Improved staging of patients with carcinoid and islet cell tumors with 18F-dihydroxy-phenyl-alanine and 11C-5-hydroxy-tryptophan positron emission tomography.
abstract: OBJECTIVE
  To evaluate and compare diagnostic sensitivity of positron emission tomography (PET) scanning in carcinoid and islet cell tumor patients with a serotonin and a catecholamine precursor as tracers.
  
  
  METHODS
  Carcinoid (n = 24) or pancreatic islet cell tumor (n = 23) patients with at least one lesion on conventional imaging including somatostatin receptor scintigraphy (SRS) and computed tomography (CT) scan underwent (11)C-5-hydroxytryptophan ((11)C-5-HTP) PET and 6-[F-18]fluoro-L-dihydroxy-phenylalanine ((18)F-DOPA) PET. PET findings were compared with a composite reference standard derived from all available imaging along with clinical and cytologic/histologic information.
  
  
  RESULTS
  In carcinoid tumor patients, per-patient analysis showed sensitivities for (11)C-5-HTP PET, (18)F-DOPA PET, SRS, and CT of 100%, 96%, 86%, 96%, respectively, and in islet cell tumors of 100%, 89%, 78%, 87%, respectively. In carcinoid patients, per-lesion analysis revealed sensitivities for (11)C-5-HTP PET, (11)C-5-HTP PET/CT, (18)F-DOPA PET, (18)F-DOPA PET/CT, SRS, SRS/CT, and CT alone of, respectively, 78%, 89%, 87%, 98%, 49%, 73%, and 63% and in islet cell tumors of 67%, 96%, 41%, 80%, 46%, 77%, and 68%, respectively. In all carcinoid patients (18)F-DOPA PET and (11)C-5-HTP PET detected more lesions than SRS (P < .001). (11)C-5-HTP PET was superior to (18)F-DOPA PET in islet cell tumors (P < .0001). In all cases, CT improved the sensitivity of the nuclear scans.
  
  
  CONCLUSIONS
  (18)F-DOPA PET/CT is the optimal imaging modality for staging in carcinoid patients and (11)C-5-HTP PET/CT in islet cell tumor patients.
authors: Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, PO Box 30.001, 9700 RB Groningen, The Netherlands.
authors: Klaas P
authors: KP
authors: Koopmans
authors: Oliver C
authors: OC
authors: Neels
authors: Ido P
authors: IP
authors: Kema
authors: Philip H
authors: PH
authors: Elsinga
authors: Wim J
authors: WJ
authors: Sluiter
authors: Koen
authors: K
authors: Vanghillewe
authors: Adrienne H
authors: AH
authors: Brouwers
authors: Pieter L
authors: PL
authors: Jager
authors: Elisabeth G E
authors: EG
authors: de Vries
mesh_terms: D006916:5-Hydroxytryptophan; D007516:Adenoma, Islet Cell / Q000000981:diagnostic imaging*; D000328:Adult; D000368:Aged; D002250:Carbon Radioisotopes; D002276:Carcinoid Tumor / Q000000981:diagnostic imaging*; D004295:Dihydroxyphenylalanine; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography / Q000379:methods; D019275:Radiopharmaceuticals; D017481:Receptors, Somatostatin / Q000378:metabolism; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D002250:Carbon Radioisotopes; D019275:Radiopharmaceuticals; D017481:Receptors, Somatostatin; D019788:Fluorodeoxyglucose F18; D004295:Dihydroxyphenylalanine; D006916:5-Hydroxytryptophan