PET/MRI May Reduce the Need for Prostate Cancer Biopsies: Study
Germany: A study published in the Journal of Nuclear Medicine has found that combined PET/MRI with MRI-based scoring accurately stratified prostate cancer risk and could have avoided biopsies in 57% of patients. The approach detected clinically significant prostate cancer with 87% accuracy, outperforming MRI alone (75%) and PET alone (81%). At high tracer-uptake thresholds, PET/MRI achieved 100% specificity, with no false-positive results. By categorizing patients into high-risk, very low-risk, and indeterminate groups, the technique may reduce unnecessary invasive biopsies and their associated complications, including pain, bleeding, infection, and urinary complications.
The study was conducted by Türkay Hekimsoy from the Department of Nuclear Medicine, School of Medicine and Health, Technical University of Munich, Germany, and colleagues. The researchers investigated whether combining 18F-flotufolastat prostate-specific membrane antigen (PSMA) PET with multiparametric MRI (mpMRI) could improve the detection of clinically significant prostate cancer (csPCa) and help identify men who could safely avoid prostate biopsy.
For the retrospective study, researchers evaluated 79 men with suspected clinically significant prostate cancer and PSA levels above 4 ng/mL. All underwent 18F-flotufolastat PET/MRI before prostate biopsy or surgery, with imaging results compared against histopathology.
Histopathology confirmed clinically significant prostate cancer (ISUP grade group ≥2) in 42 patients, while 37 patients had no clinically significant disease.
Key findings included:
- The combined PET/MRI approach achieved an area under the curve (AUC) of 87.1%, compared with 75.2% for MRI alone and 80.7% for PET alone, indicating better overall diagnostic performance.
- MRI using a PI-RADS score of 3 or higher and PET using a low SUVmax threshold (>4.5) showed similar sensitivity for detecting clinically significant prostate cancer (90% vs. 91%), although specificity remained modest.
- Raising the PET SUVmax threshold to greater than 10.0 increased specificity to 100%, eliminating false-positive findings in the study cohort.
- The combined imaging strategy identified 28% of patients with a very high probability of clinically significant prostate cancer and 29% with a very low likelihood of disease, allowing clinicians to distinguish patients who might benefit from immediate treatment from those who could potentially avoid biopsy.
- Overall, the imaging-based strategy could have eliminated the need for prostate biopsy in 57% of patients included in the study.
The researchers noted that although prostate biopsy remains the standard for diagnosing prostate cancer, it is invasive and carries risks including pain, bleeding, infection, and urinary complications. A reliable non-invasive alternative could reduce unnecessary biopsies and improve patient care.
The authors concluded that 18F-flotufolastat PSMA PET/mpMRI may help classify patients into high-, low-, and indeterminate-risk groups, potentially reducing biopsy use. They called for larger prospective studies to confirm its role in enabling biopsy-free diagnosis for selected patients.
Reference:
Toward a Biopsy-Free Diagnosis of Prostate Cancer: Potential of Combined 18F-Flotufolastat PSMA PET and mpMRI. Türkay Hekimsoy, Andreas P. Sauter, Robert Tauber, Thomas Horn, Matthias Jahnen, Fabian Horné, Julian Q. Petzold, Daniel Sasse, Isabel Rauscher, Matthias Eiber, Wolfgang A. Weber, Bernd M. Erber. Journal of Nuclear Medicine Jul 2026, jnumed.125.271916; DOI: 10.2967/jnumed.125.271916
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