title: 68Ga-PSMA-PET/CT in Patients With Biochemical Prostate Cancer Recurrence and Negative 18F-Choline-PET/CT.
abstract: OBJECTIVE
  Investigating the value of Ga-PSMA-PET/CT in biochemically recurring prostate cancer patients with negative F-choline-PET/CT.
  
  
  METHODS
  One hundred thirty-nine consecutive patients with biochemical recurrence after curative (surgery and/or radiotherapy) therapy were offered participation in this sequential clinical imaging approach. Patients first underwent an F-choline-PET/CT. If negative, an additional Ga-PSMA-PET/CT was offered. One hundred twenty-five of 139 eligible patients were included in the study; 32 patients underwent additional Ga-PSMA-PET/CT. Patients with equivocal findings (n = 5) on F-choline-PET/CT and those who declined the additional Ga-PSMA-PET/CT (n = 9) were excluded. Images were analyzed visually for the presence of suspicious lesions. Findings on PET/CT were correlated with PSA level, PSA doubling time (dt), and PSA velocity (vel).
  
  
  RESULTS
  The overall detection rates were 85.6% (107/125) for the sequential imaging approach and 74.4% (93/125) for F-choline-PET/CT alone. Ga-PSMA-PET/CT detected sites of recurrence in 43.8% (14/32) of the choline-negative patients. Detection rates of the sequential imaging approach and F-choline-PET/CT alone increased with higher serum PSA levels and PSA vel. Subgroup analysis of Ga-PSMA-PET/CT in F-choline negative patients revealed detection rates of 28.6%, 45.5%, and 71.4% for PSA levels of 0.2 or greater to less than 1 ng/mL, 1 to 2 ng/mL, and greater than 2 ng/mL, respectively.
  
  
  CONCLUSIONS
  The sequential imaging approach designed to limit Ga-PSMA imaging to patients with negative choline scans resulted in high detection rates. Ga-PSMA-PET/CT identified sites of recurrent disease in 43.8% of the patients with negative F-choline PET/CT scans.
authors.affiliation: From the Departments of *Nuclear Medicine, †Urology, and ‡Radiation Oncology, University Hospital of Würzburg, Würzburg; §Department of Radiation Oncology, Klinikum Ansbach, Ansbach; ∥Department of Nuclear Medicine, Technische Universität München, Munich, Germany; ¶Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA; #Department of Nuclear Medicine-PET/CT Oncologic & Endocrine Sections, Rovigo Hospital, Rovigo, Italy; **Department of Radiology, University Hospital of Würzburg, Würzburg, Germany; ††Scintomics GmbH, Fürstenfeldbruck; and ‡‡Pharmaceutical Radiochemistry, Technische Universität München, Munich, Germany.
authors.forename: Christina
authors.initials: C
authors.lastname: Bluemel
authors.forename: Markus
authors.initials: M
authors.lastname: Krebs
authors.forename: Bülent
authors.initials: B
authors.lastname: Polat
authors.forename: Fränze
authors.initials: F
authors.lastname: Linke
authors.forename: Matthias
authors.initials: M
authors.lastname: Eiber
authors.forename: Samuel
authors.initials: S
authors.lastname: Samnick
authors.forename: Constantin
authors.initials: C
authors.lastname: Lapa
authors.forename: Michael
authors.initials: M
authors.lastname: Lassmann
authors.forename: Hubertus
authors.initials: H
authors.lastname: Riedmiller
authors.forename: Johannes
authors.initials: J
authors.lastname: Czernin
authors.forename: Domenico
authors.initials: D
authors.lastname: Rubello
authors.forename: Thorsten
authors.initials: T
authors.lastname: Bley
authors.forename: Saskia
authors.initials: S
authors.lastname: Kropf
authors.forename: Hans-Juergen
authors.initials: HJ
authors.lastname: Wester
authors.forename: Andreas K
authors.initials: AK
authors.lastname: Buck
authors.forename: Ken
authors.initials: K
authors.lastname: Herrmann
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000954:Antigens, Surface; D002794:Choline / Q000031:analogs & derivatives*; D005710:Gallium Radioisotopes / Q000378:metabolism*; D043425:Glutamate Carboxypeptidase II; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging*; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology
chemical_list: D000954:Antigens, Surface; D005710:Gallium Radioisotopes; C516370:fluoromethylcholine; C473848:FOLH1 protein, human; D043425:Glutamate Carboxypeptidase II; D002794:Choline