title: Biodistribution and radiation dosimetry of (68)Ga-PSMA HBED CC-a PSMA specific probe for PET imaging of prostate cancer.
abstract: OBJECTIVE
  Positron emission tomography (PET) agents targeting the prostate-specific membrane antigen (PSMA) are currently under broad clinical and scientific investigation. (68)Ga-PSMA HBED-CC constitutes the first (68)Ga-labelled PSMA-inhibitor and has evolved as a promising agent for imaging PSMA expression in vivo. The aim of this study was to evaluate the whole-body distribution and radiation dosimetry of this new probe.
  
  
  METHODS
  Five patients with a history or high suspicion of prostate cancer were injected intravenously with a mean of 139.8 ± 13.7 MBq of (68)Ga-PSMA HBED-CC (range 120-158 MBq). Four static skull to mid-thigh scans using a whole-body fully integrated PET/MR-system were performed 10 min, 60 min, 130 min, and 175 min after the tracer injection. Time-dependent changes of the injected activity per organ were determined. Mean organ-absorbed doses and effective doses (ED) were calculated using OLINDA/EXM.
  
  
  RESULTS
  Injection of a standard activity of 150 MBq (68)Ga-PSMA HBED-CC resulted in a median effective dose of 2.37 mSv (Range 1.08E-02 - 2.46E-02 mSv/MBq). The urinary bladder wall (median absorbed dose 1.64E-01 mGv/MBq; range 8.76E-02 - 2.91E-01 mGv/MBq) was the critical organ, followed by the kidneys (median absorbed dose 1.21E-01 mGv/MBq; range 7.16E-02 - 1.75E-01), spleen (median absorbed dose 4.13E-02 mGv/MBq; range 1.57E-02 - 7.32E-02 mGv/MBq) and liver (median absorbed dose 2.07E-02 mGv/MBq; range 1.80E-02 - 2.57E-02 mGv/MBq). No drug-related pharmacological effects occurred.
  
  
  CONCLUSIONS
  The use of (68)Ga-PSMA HBED-CC results in a relatively low radiation exposure, delivering organ doses that are comparable to those of other (68)Ga-labelled PSMA-inhibitors used for PET-imaging. Total effective dose is lower than for other PET-agents used for prostate cancer imaging (e.g. (11)C- and (18)F-Choline).
authors.affiliation: Department of Nuclear Medicine, Technische Universität München, Klinikum rechts der Isar; Ismaningerstrasse 22, 81675, Munich, Germany. christian.pfob@tum.de.
authors.forename: Christian H
authors.initials: CH
authors.lastname: Pfob
authors.affiliation: Department of Nuclear Medicine, Technische Universität München, Klinikum rechts der Isar; Ismaningerstrasse 22, 81675, Munich, Germany.
authors.forename: Sibylle
authors.initials: S
authors.lastname: Ziegler
authors.affiliation: Department of Nuclear Medicine, Technische Universität München, Klinikum rechts der Isar; Ismaningerstrasse 22, 81675, Munich, Germany.
authors.forename: Frank Philipp
authors.initials: FP
authors.lastname: Graner
authors.affiliation: Department of Nuclear Medicine, Technische Universität München, Klinikum rechts der Isar; Ismaningerstrasse 22, 81675, Munich, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Köhner
authors.affiliation: Department of Nuclear Medicine, Technische Universität München, Klinikum rechts der Isar; Ismaningerstrasse 22, 81675, Munich, Germany.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Schachoff
authors.affiliation: Department of Nuclear Medicine, Technische Universität München, Klinikum rechts der Isar; Ismaningerstrasse 22, 81675, Munich, Germany.
authors.forename: Birgit
authors.initials: B
authors.lastname: Blechert
authors.affiliation: Chair of Pharmaceutical Radiochemistry, Department Chemie, Technische Universität München, Walther-Meissner-Str. 3, 85748, Garching, Germany.
authors.forename: Hans-Jürgen
authors.initials: HJ
authors.lastname: Wester
authors.affiliation: Department of Nuclear Medicine, Technische Universität München, Klinikum rechts der Isar; Ismaningerstrasse 22, 81675, Munich, Germany.
authors.forename: Klemens
authors.initials: K
authors.lastname: Scheidhauer
authors.affiliation: Department of Nuclear Medicine, Technische Universität München, Klinikum rechts der Isar; Ismaningerstrasse 22, 81675, Munich, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Schwaiger
authors.affiliation: Department of Urology, Technische Universität München, Klinikum rechts der Isar, Ismaninger Str. 22, 81675, Munich, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Maurer
authors.affiliation: Department of Nuclear Medicine, Technische Universität München, Klinikum rechts der Isar; Ismaningerstrasse 22, 81675, Munich, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Eiber
mesh_terms: D065638:Absorption, Radiation; D000368:Aged; D000954:Antigens, Surface; D004492:Edetic Acid / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D043425:Glutamate Carboxypeptidase II / Q000493:pharmacokinetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015336:Molecular Probe Techniques; D009928:Organ Specificity; D049268:Positron-Emission Tomography / Q000379:methods*; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism*; D011829:Radiation Dosage; D000069079:Radiation Exposure / Q000032:analysis*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D014018:Tissue Distribution; D014915:Whole-Body Counting
chemical_list: D000954:Antigens, Surface; D019275:Radiopharmaceuticals; C075313:N,N'-bis(2-hydroxy-5-(ethylene-beta-carboxy)benzyl)ethylenediamine N,N'-diacetic acid; D004492:Edetic Acid; C473848:FOLH1 protein, human; D043425:Glutamate Carboxypeptidase II
keywords: 68Ga-PSMA HBED-CC; PET; Prostate cancer; Radiation dosimetry