Cost Analysis of PSMA-PET in the PROSPET-BX Trial

Background: The PROSPET-BX trial compared 68GaPSMA-11 PET/CT (PSMA-PET) with multiparametric MRI (mpMRI) in parallel in men with suspicion of prostate cancer (PCa) after at least one previously negative biopsy (ClinicalTrials.gov:NCT05297162; GR-2018-12366240). In this study, we performed the cost analysis of the two imaging modalities with respect to the detection of clinically significant PCa (csPCa). Methods: We analyzed the data from patients enrolled in the trial who met the inclusion criteria. For the cost analysis, we identified six competing triage strategies, each defined as a binary decision rule for referral to prostate biopsy: (1) biopsy-all; (2) elevated PSA-density (PSAD; biopsy if PSAD > 0.15 ng/mL/cc; (3) mpMRI positive (PIRADS 3–5); (4) PSMA-PET positive (PRIMARY 3–5); (5) mpMRI or PSMA-PET positive; (6) PSAD and mpMRI. For each strategy, we yielded sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for csPCa. Direct hospital costs were modeled from a provider perspective, incorporating testing and procedural costs. Unit costs (in EUR) were sourced from our institutional accounting records. Pairwise cost-effectiveness comparisons were performed using incremental cost-effectiveness ratio (ICER) and incremental net benefit (INB). Results: Among the six triage strategies evaluated, the “biopsy-all” approach achieved perfect sensitivity, whereas the PSAD + mpMRI pathway was the most parsimonious strategy but missed 14 csPCa cases (53.8%). The combined “mpMRI or PSMA-PET” strategy maximized detection (22 cPCa, missing only 4) at an intermediate cost (EUR 81.991 total; EUR 3.727 per csPCa). The pairwise comparison of each strategy with mpMRI alone showed for the mpMRI or PSMA-PET pathway a low ICER (~EUR 2.900/extra csPCa), with consistently positive and increasing INB across higher WTP (willingness-to-pay). Therefore, this combination provided the most favorable cost-effectiveness profile, balancing detection, efficiency, and cost. Conclusions: To the best of our knowledge, this is the first cost analysis study to compare different strategies incorporating PSMA-PET in the re-biopsy setting, demonstrating that the combined “mpMRI or PSMA-PET” pathway is the most cost-effective diagnostic pathway for csPCa detection.