title: Simultaneous68Ga-PSMA HBED-CC PET/MRI Improves the Localization of Primary Prostate Cancer.
abstract: Ligands of the prostate-specific membrane antigen (PSMA) show promising results in positron emission tomography (PET) imaging of prostate cancer (PCa).
  
  
  
  To compare the diagnostic performance of simultaneous gallium 68 (68Ga)-PSMA HBED-CC PET/magnetic resonance imaging (MRI) for localization of primary PCa with multiparametric magnetic resonance imaging (mpMRI) and PET alone.
  
  
  
  We performed68Ga-PSMA HBED-CC PET/MRI in 66 men with biopsy-proven PCa.
  
  
  
  PET, mpMRI, and combined68Ga-PSMA HBED-CC PET/MRI were independently evaluated using Prostate Imaging Reporting and Data System criteria or a 5-point Likert scale.
  
  
  
  The prostate was divided into sextants for histopathology and coregistered with imaging. Diagnostic performance for localization of malignancy was calculated based on receiver operating characteristics analysis for each modality. Regional quantitative PET tracer uptake was recorded; uptake ratio was defined as the ratio of malignant to nonmalignant prostate tissue.
  
  
  
  A total of 53 of 66 patients were eligible for analysis. mpMRI, PET, and PET/MRI detected cancer in 66% (35 of 53), 92% (49 of 53), and 98% (52 of 53) of the patients, respectively. Overall, 202 of 318 sextants (63.5%) contained cancer at pathologic examination. Simultaneous PET/MRI statistically outperformed mpMRI (area under the curve [AUC]: 0.88 vs 0.73; p<0.001) and PET imaging (AUC: 0.88 vs 0.83; p=0.002) for localization of PCa. Compared with mpMRI, PET imaging was more accurate (AUC: 0.83 vs 0.73; p=0.003). PET provided a high uptake ratio between malignant versus nonmalignant tissue (5.02 [range: 0.89-29.8]), but no significant correlation was observed between quantitative PET parameters and Gleason score or prostate-specific antigen value.
  
  
  
  Simultaneous68Ga-PSMA HBED-CC PET/MRI improves diagnostic accuracy for PCa localization both compared with mpMRI and with PET imaging alone. Further prospective studies are warranted to evaluate its potential (eg, for biopsy guidance).
  
  
  
  We examined gallium 68 (68Ga)-prostate-specific membrane antigen (PSMA) HBED-CC positron emission tomography/magnetic resonance imaging (PET/MRI) for primary prostate cancer (PCa) and compared it with multiparametric MRI and PET alone. Our results indicate a higher diagnostic accuracy for68Ga-PSMA HBED-CC PET/MRI that may help localize PCa.
authors.affiliation: Department of Nuclear Medicine, Technische Universität München, Klinikum rechts der Isar, Munich, Germany. Electronic address: matthias.eiber@tum.de.
authors.forename: Matthias
authors.initials: M
authors.lastname: Eiber
authors.affiliation: Department of Pathology, Technische Universität München, Klinikum rechts der Isar, Munich, Germany.
authors.forename: Gregor
authors.initials: G
authors.lastname: Weirich
authors.affiliation: Institute of Radiology, Technische Universität München, Klinikum rechts der Isar, Munich, Germany.
authors.forename: Konstantin
authors.initials: K
authors.lastname: Holzapfel
authors.affiliation: Department of Nuclear Medicine, Technische Universität München, Klinikum rechts der Isar, Munich, Germany; Department of Nuclear Medicine, University Hospital Ulm, Ulm, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Souvatzoglou
authors.affiliation: Institute of Medical Statistics and Epidemiology, Technische Universität München, Klinikum rechts der Isar, Munich, Germany.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Haller
authors.affiliation: Department of Nuclear Medicine, Technische Universität München, Klinikum rechts der Isar, Munich, Germany.
authors.forename: Isabel
authors.initials: I
authors.lastname: Rauscher
authors.affiliation: Department of Nuclear Medicine, Technische Universität München, Klinikum rechts der Isar, Munich, Germany; Department of Nuclear Medicine, University Hospital Ulm, Ulm, Germany.
authors.forename: Ambros J
authors.initials: AJ
authors.lastname: Beer
authors.affiliation: Pharmaceutical Radiochemistry, Technische Universität München, Garching, Germany.
authors.forename: Hans-Jürgen
authors.initials: HJ
authors.lastname: Wester
authors.affiliation: Department of Urology, Technische Universität München, Klinikum rechts der Isar, Munich, Germany.
authors.forename: Juergen
authors.initials: J
authors.lastname: Gschwend
authors.affiliation: Department of Nuclear Medicine, Technische Universität München, Klinikum rechts der Isar, Munich, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Schwaiger
authors.affiliation: Department of Urology, Technische Universität München, Klinikum rechts der Isar, Munich, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Maurer
mesh_terms: D000368:Aged; D001706:Biopsy / Q000379:methods; D057186:Comparative Effectiveness Research; D061827:Dimensional Measurement Accuracy; D005710:Gallium Radioisotopes / Q000494:pharmacology; D005858:Germany; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D011467:Prostate / Q000000981:diagnostic imaging / Q000473:pathology; D017430:Prostate-Specific Antigen / Q000032:analysis*; D011471:Prostatic Neoplasms / Q000175:diagnosis / Q000473:pathology; D012372:ROC Curve; D019275:Radiopharmaceuticals / Q000494:pharmacology
chemical_list: D005710:Gallium Radioisotopes; D019275:Radiopharmaceuticals; D017430:Prostate-Specific Antigen
keywords: (68)Ga-PSMA HBED-CC PET/MRI; Histopathology; Localization; Primary prostate cancer; mpMRI