We carried out this study to compare Glu-NH-CO-NH-Lys-(Ahx) [68Ga(HBED-CC)] [68Ga prostate-specific membrane antigen-11 (PSMA-11)] PET with multiparametric MRI (mpMRI) for the staging of high-risk prostate cancer.Patients and methods
This was a prospective study in which 36 patients with high-risk prostate cancer were included. The criteria for inclusion were biopsy-proven prostate cancer with a serum prostate specific antigen of at least 20 and/or Gleason’s score of at least 8. Each patient then underwent both gallium-68 (68Ga)-PSMA PET/computed tomography (CT) and mpMRI including diffusion-weighted whole-body imaging with background body signal suppression within an interval of 1 week and both modalities were compared for staging of primary disease, lymph node, and distant metastasis.Results
The median age of the 36 patients included was 65 years (range: 44–80 years) and the median prostate specific antigen was 94.3 ng/ml (range: 20–19005 ng/ml). Concordance for localization of primary on 68Ga-PSMA PET/CT and MRI was observed in 19/36 (52.7%) patients. Concurrence for T staging on 68Ga-PSMA and MRI was observed in 58.3% of patients. 68Ga-PSMA PET/CT detected higher numbers of patients with regional (29) and nonregional (15) lymph nodes in comparison with MRI (20 and 5, respectively). Concurrence for regional and nonregional lymph node staging was observed in 72.2% of patients. Additional sites of metastatic disease reported on 68Ga-PSMA PET/CT were to the skeleton in one patient, the lung in two patients, and the liver in one patient.Conclusion
This study suggests that 68Ga-PSMA PET/CT is useful for lymph node and metastases staging in high-risk prostate cancers, whereas its utility for staging of disease in the prostate is limited.