68Ga-prostate specific membrane antigen (PSMA) positron emission tomography (PET) for primary staging of high-risk prostate cancer: a systematic review

Abstract

Purpose: To systematically review currently available data on ⁶⁸Ga-prostate specific membrane antigen (PSMA) positron emission tomography (PET) used for the primary staging of high-risk prostate cancer.

Methods: We performed critical reviews of EMBASE, Web of Science (including MEDLINE) and Cochrane databases in October 2016 according to the Preferred Reporting Items for Systematic Review and Meta-analysis statement. We included studies that utilized ⁶⁸Ga-PSMA PET for primary staging of prostate cancer. Quality was assessed using the Critical Appraisal Skills Programme checklist for diagnostic test studies.

Results: Following our systematic search strategy, 12 studies were included for assessment. These studies comprised a total of 322 patients who underwent ⁶⁸Ga-PSMA PET scanning for the purpose of primary staging. Only 5 of these studies included histopathologic correlation data. High variation in methodology and outcomes such as sensitivity (range 33-99%) and specificity (> 90%) was seen across all studies. The ability of ⁶⁸Ga-PSMA PET to detect malignant lesions was evident across studies, with most studies demonstrating increased detection rates with respect to conventional imaging modalities.

Conclusions: In the primary staging of prostate cancer ⁶⁸Ga-PSMA PET appears to outperform traditional imaging modalities. Overall, there are few high-quality studies investigating ⁶⁸Ga-PSMA PET in this sub-group highlighting the need for formal assessment of PSMA PET in the form of large-volume, prospective studies.

Keywords: Imaging; PSMA; Positron emission tomography; Prostate cancer; Prostate-specific membrane antigen.