title: PET with L-[1-carbon-11]-tyrosine to visualize tumors and measure protein synthesis rates.
abstract: We studied the potential of PET with L-[1-11C]-tyrosine (TYR) to visualize tumors outside the central nervous system and to quantify their protein synthesis rates (PSRs).
  
  
  METHODS
  Twenty-two patients suspected of having a malignant tumor underwent a PET study with TYR before biopsy. The PSR in nanomoles per milliliter tumor tissue per minute as well as the PSR in contralateral normal tissue, standardized uptake values (SUVs) and tumor-to-nontumor-ratios (T/N ratios) were calculated.
  
  
  RESULTS
  Fifteen of the 16 malignancies (94%) were correctly visualized as a hot spot. A chondrosarcoma of the sacrum was not visualized. Of the six patients with benign lesions, cold spots were correctly identified in four (67%). A benign schwannoma and an intramuscular hemangioma of the forearm were visualized as hot spots. PSR in tumor tissue was higher than in the corresponding contralateral normal tissues. PSR and SUV in malignant tumors were higher than in benign tumors.
  
  
  CONCLUSIONS
  TYR appears to be a good tracer for imaging malignancies. The PSR, which was higher in malignant tumors than in normal tissue and the studied benign lesions, could be quantified and correlated with the SUV.
authors.affiliation: PET Center, Groningen University Hospital, The Netherlands.
authors.forename: A C
authors.initials: AC
authors.lastname: Kole
authors.forename: J
authors.initials: J
authors.lastname: Pruim
authors.forename: O E
authors.initials: OE
authors.lastname: Nieweg
authors.forename: R J
authors.initials: RJ
authors.lastname: van Ginkel
authors.forename: H J
authors.initials: HJ
authors.lastname: Hoekstra
authors.forename: H
authors.initials: H
authors.lastname: Schraffordt Koops
authors.forename: W
authors.initials: W
authors.lastname: Vaalburg
mesh_terms: D000328:Adult; D000368:Aged; D002250:Carbon Radioisotopes / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism*; D014176:Protein Biosynthesis; D012680:Sensitivity and Specificity; D014055:Tomography, Emission-Computed; D014443:Tyrosine / Q000493:pharmacokinetics
chemical_list: D002250:Carbon Radioisotopes; D014443:Tyrosine