title: Diagnostic value of additional68Ga-PSMA-PET before223Ra-dichloride therapy in patients with metastatic prostate carcinoma.
abstract: OBJECTIVE
  Medical imaging plays an important role in selecting patients with metastatic castration-resistant prostate cancer for223Ra-dichloride therapy of bone metastases. The purpose of this study was to investigate whether68Ga-PSMA-PET has incremental value over conventional imaging for selecting patients suitable for223Ra-dichloride therapy.
  
  
  METHODS
  In 27 consecutive patients referred for223Ra-dichloride therapy additional68Ga-PSMA-PET/CT was performed and tracer distribution was evaluated systematically with respect to the detection of visceral metastases and bone metastases with inadequate uptake on bone scintigraphy.
  
  
  RESULTS
  In 4 patients (15 %)68Ga-PSMA-PET revealed previously unknown visceral metastases (3 liver, 1 adrenal gland), which changed the therapeutic decision in 2 cases. PET revealed more extended tumour involvement in the bone compared to bone scintigraphy in 9 patients (33 %). In 3 of these, the mismatch was extensive enough to question suitability for223Ra-dichloride therapy.
  
  
  CONCLUSIONS
  Additional68Ga-PSMA-PET as a gatekeeper between conventional staging and223Ra-dichloride therapy can provide valuable additional information with regard to visceral metastases and tumour manifestations without adequate bone mineral turnover. It may lead to a change in therapeutic management in a significant number of patients and should therefore be considered in future clinical trials.
authors.affiliation: Axel Bräuer, Department of Nuclear Medicine,, University Hospital Münster, Albert-Schweitzer-Campus 1, 48149 Münster, Germany, Phone: +49 251 8347362, Fax: +49 251 8347363, E-Mail: axel.braeuer@ukmuenster.de.
authors.forename: Axel
authors.initials: A
authors.lastname: Bräuer
authors.forename: Kambiz
authors.initials: K
authors.lastname: Rahbar
authors.forename: Julia
authors.initials: J
authors.lastname: Konnert
authors.forename: Martin
authors.initials: M
authors.lastname: Bögemann
authors.forename: Lars
authors.initials: L
authors.lastname: Stegger
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000000981:diagnostic imaging / Q000532:radiotherapy* / Q000556:secondary*; D004492:Edetic Acid / Q000031:analogs & derivatives*; D005709:Gallium Isotopes; D005710:Gallium Radioisotopes; D006801:Humans; D008297:Male; D008875:Middle Aged; D009842:Oligopeptides; D049268:Positron-Emission Tomography / Q000379:methods*; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D011868:Radioisotopes / Q000627:therapeutic use; D019275:Radiopharmaceuticals / Q000627:therapeutic use; D011883:Radium / Q000627:therapeutic use*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
chemical_list: D005709:Gallium Isotopes; D005710:Gallium Radioisotopes; D009842:Oligopeptides; D011868:Radioisotopes; D019275:Radiopharmaceuticals; C000718244:gallium 68 PSMA-11; D004492:Edetic Acid; C581106:radium Ra 223 dichloride; D011883:Radium
keywords: 223Ra-dichloride; 68Ga-PSMA-PET; Xofigo®; bone metastases; bone scintigraphy; prostate cancer