title: 68Ga-PSMA I&T PET/CT for assessment of prostate cancer: evaluation of image quality after forced diuresis and delayed imaging.
abstract: OBJECTIVE
  Urinary radiotracer excretion of68Ga-Labelled prostate-specific membrane antigen (PSMA) ligands may complicate the assessment of the prostate region and differentiation of lymph nodes from ureteral activity. The aim of this study was to assess the value of delayed imaging after forced diuresis.
  
  
  METHODS
  Sixty-six patients underwent68Ga-PSMA I&T PET/CT for evaluation of prostate cancer at 60 min post-injection. In subgroups of patients, this was amended by delayed imaging after 180 min post-injection, preceded by furosemide and oral hydration early, at the time of tracer injection, or delayed, at 100 min post-injection. Urinary tracer activity within the bladder and focal ureteral activity was analyzed.
  
  
  RESULTS
  After forced diuresis, linear and focal visualization of ureters was significantly reduced. After delayed furosemide, mean and peak bladder activity decreased (p < 0.001), and image quality of the prostate region improved on delayed images (p < 0.001). Early furosemide co-injection with tracer resulted in increased mean and peak bladder activity (p < 0.001) and in deteriorated image quality of the prostate region on delayed images (p = 0.008).
  
  
  CONCLUSIONS
  Ga-PSMA I&T PET/CT delayed imaging after forced diuresis can improve the assessment of prostate region and pelvic lymph nodes by removing excreted tracer from the lower urinary tract.
  
  
  CONCLUSIONS
  • Forced diuresis can improve image quality in68Ga-PSMA I&T. • After forced diuresis, linear and focal visualization of ureters was reduced. • Timing of diuresis relative to68Ga-PSMA I&T injection is important. • Early furosemide co-injection with tracer resulted in deteriorated image quality on delayed images. • After delayed furosemide, image quality improved on delayed images.
authors.affiliation: Department of Nuclear Medicine, Hannover Medical School, Carl-Neuberg-Str. 1, D-30625, Hannover, Germany. Derlin.Thorsten@mh-hannover.de.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Derlin
authors.affiliation: Department of Nuclear Medicine, Hannover Medical School, Carl-Neuberg-Str. 1, D-30625, Hannover, Germany.
authors.forename: Desiree
authors.initials: D
authors.lastname: Weiberg
authors.affiliation: Department of Urology and Urologic Oncology, Hannover Medical School, Hannover, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: von Klot
authors.affiliation: Pharmaceutical Radiochemistry, Technische Universität München, Garching, Germany.
authors.forename: Hans-Jürgen
authors.initials: HJ
authors.lastname: Wester
authors.affiliation: Department of Radiation Oncology, Hannover Medical School, Hannover, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Henkenberens
authors.affiliation: Department of Nuclear Medicine, Hannover Medical School, Carl-Neuberg-Str. 1, D-30625, Hannover, Germany.
authors.forename: Tobias L
authors.initials: TL
authors.lastname: Ross
authors.affiliation: Department of Radiation Oncology, Hannover Medical School, Hannover, Germany.
authors.forename: Hans
authors.initials: H
authors.lastname: Christiansen
authors.affiliation: Department of Urology, Campus Lübeck, University Hospital Schleswig-Holstein, Lübeck, Germany.
authors.forename: Axel S
authors.initials: AS
authors.lastname: Merseburger
authors.affiliation: Department of Nuclear Medicine, Hannover Medical School, Carl-Neuberg-Str. 1, D-30625, Hannover, Germany.
authors.forename: Frank M
authors.initials: FM
authors.lastname: Bengel
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000954:Antigens, Surface; D004231:Diuresis / Q000502:physiology; D005260:Female; D043425:Glutamate Carboxypeptidase II; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D010388:Pelvis / Q000473:pathology; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D019275:Radiopharmaceuticals
chemical_list: D000954:Antigens, Surface; D019275:Radiopharmaceuticals; C473848:FOLH1 protein, human; D043425:Glutamate Carboxypeptidase II
keywords: Dual time-point; Forced dieresis; Furosemide; PET/CT; PSMA