There’s been a growing number of studies comparing 68Ga-PSMA PET/CT and mpMRI’s effectiveness along the prostate cancer pathway, but new research suggests that the modalities might be particularly effective if used together early in the diagnostic process.
The Study – A team of Australian researchers reviewed pre-operative mpMRI and 68Ga-PSMA PET/CT exams from 1,123 men (median PSA = 6), comparing their imaging results and histology findings. Here’s what they discovered:
- mpMRI identified tumors in 93 men (8%) that were missed by 68Ga-PSMA PET/CT
- 68Ga-PSMA PET/CT spotted tumors in 117 men (10%) that mpMRI missed
- The combined modalities identified index tumors with Gleason Scores of ≥3+4 in 92% of men (vs. 80% w/ only mpMRI & 82% w/ only PSMA PET/CT)
- 68Ga-PSMA PET/CT and mpMRI performed similarly for lesion/tumor detection and localization
Better Assessments and Decisions – In addition to identifying more tumors, mpMRI and 68Ga-PSMA PET/CT’s combined localization accuracy might improve biopsy targeting, leading to more accurate tumor grading and better management decisions.
More Necessary Biopsies – Meanwhile, patients with negative mpMRI and 68Ga-PSMA PET/CT findings would likely have a low risk of clinically significant prostate cancer, making them solid candidates for active PSA monitoring and allowing them to avoid unnecessary biopsies.
The Takeaway – This approach needs a lot more research and PSMA tracers currently only have FDA approval for patients with metastatic prostate cancer or biochemical recurrence, so 68Ga-PSMA PET/CT won’t be combined with mpMRI in early diagnostic exams very soon. That said, this study suggests that we’ll see more future efforts to combine and evaluate mpMRI + 68Ga-PSMA PET/CT as an early diagnostic step.