Intraindividual Comparison of ¹⁸F-PSMA-1007 PET/CT, Multiparametric MRI, and Radical Prostatectomy Specimens in Patients with Primary Prostate Cancer: A Retrospective, Proof-of-Concept Study

Abstract

Ga-prostate-specific membrane antigen (PSMA)-11 PET/CT represents an advanced method for the staging of primary prostate cancer (PCa) and diagnosis of recurrent or metastatic PCa. However, because of the narrow availability of Ga the development of alternative tracers is of high interest. The objective of this study was to examine the value of the new PET tracerF-PSMA-1007 for the staging of local disease by comparing it with multiparametric MRI (mpMRI) and radical prostatectomy (RP) histopathology. In 2016,F-PSMA-1007 PET/CT was performed in 10 men with biopsy-confirmed high-risk PCa. Nine patients underwent mpMRI in the process of primary diagnosis. Consecutively, RP was performed in all 10 men. Agreement analysis was performed retrospectively. PSMA staining was added for representative sections in RP specimen slices. Localization and agreement analysis of F-PSMA-1007 PET/CT, mpMRI, and RP specimens was performed by dividing the prostate into 38 sections as described in the prostate imaging reporting and data system (PI-RADS) (version 2). Sensitivity, specificity, positive predictive values, negative predictive values (NPVs), and accuracy were calculated for total and near-total agreement.F-PSMA-1007 PET/CT had an NPV of 68% and an accuracy of 75%, and mpMRI had an NPV of 88% and an accuracy of 73% for total agreement. Near-total agreement analysis resulted in an NPV of 91% and an accuracy of 93% for F-PSMA-1007 PET/CT and 91% and 87% for mpMRI, respectively. Retrospective combination of mpMRI and PET/CT had an accuracy of 81% for total and 93% for near-total agreement. Comparison with RP histopathology demonstrates that F-PSMA-1007 PET/CT is promising for accurate local staging of PCa.

Diagnostic accuracy of 68Ga‐prostate‐specific membrane antigen (PSMA) positron‐emission tomography (PET) and multiparametric (mp)MRI to detect intermediate‐grade intra‐prostatic prostate cancer using whole‐mount pathology: impact of the addition of 68Ga‐PSMA PET to mpMRI

“…Several other series have evaluated the ability of PSMA‐PET and mpMRI to detect intra‐prostatic PCa. These series differ in methods and/or patient populations, therefore, no direct comparison can be made between the diagnostic accuracy of PSMA‐PET observed in the present results and that observed in these previous series .…”

“…This approach may have biased the statistics for both PSMA‐PET and mpMRI (more segments classified as true positive or negative); therefore, we clustered our data; that is, we evaluated the diagnostic accuracy per patient by clustering all the segments of a prostate that belonged to one patient (Table ), and found that the results did not differ. Nonetheless, given the potential bias of a segmental analysis, we make no statement regarding the screening capabilities of the individual techniques, nor have we compared the diagnostic accuracy of our PSMA‐PET results with those of other published series , but have merely used this approach to compare PSMA‐PET and mpMRI in a surgical cohort.…”

“…Prostate‐specific membrane antigen (PSMA) is expressed on the cell surface of higher‐grade PCa . PSMA‐positron‐emission tomography (PET)/CT (PSMA‐PET) has been shown to have a high specificity in the detection of PCa lymph node metastases ; however, the diagnostic accuracy of PSMA‐PET to detect significant intra‐prostatic PCa has not yet been evaluated, except in high‐risk disease . Evidence for its ability to differentiate significant PCa from low‐grade (ISUP grade 1) PCa is lacking.…”

Fine‐tuning of the automated [18F]PSMA‐1007 radiosynthesis

“…Several clinical trials have demonstrated the potential of [ 18 F]PSMA‐1007 as an attractive radiolabeled tracer for PC PET imaging . One clear advantage of [ 18 F]PSMA‐1007 is the non‐urinary excretion, which can benefit clinical decision making in local recurrence . Here, we describe the implementation and optimization of the recently published one‐step radiosynthesis of [ 18 F]PSMA‐1007 using commercially available modules …”

“…[13][14][15] One clear advantage of [ 18 F] PSMA-1007 is the non-urinary excretion, which can benefit clinical decision making in local recurrence. 12,[16][17][18] Here, we describe the implementation and optimization of the recently published one-step radiosynthesis of [ 18 F]PSMA-1007 using commercially available modules. 19…”