Study Finds Advanced Imaging Significantly Reduces Unnecessary Prostate Biopsies

Many men with suspected prostate cancer face an invasive biopsy when magnetic resonance imaging (MRI) is inconclusive. Biopsies can be uncomfortable, carry risks, and may contribute to overdiagnosis and overtreatment. To help address this challenge, clinicians evaluated whether a PSMA PET/CT scan could more precisely triage patients after MRI. New data indicate the scan may safely halve the number of biopsies while maintaining detection of clinically significant disease.

The Australia-wide Phase III PRIMARY2 trial, led by Peter MacCallum Cancer Center in Melbourne and St Vincent's Hospital in Sydney, assessed PSMA PET/CT in men at higher risk who had a normal MRI. Results were presented at the European Association of Urology Congress (EAU26) in London. Participants were randomly assigned to proceed with a standard biopsy or undergo PSMA PET/CT to guide next steps.

PSMA PET/CT uses a molecule that binds to prostate cancer cells and makes them appear as bright spots on the scan. The signal is strongest in more aggressive cancers, supporting risk stratification. This approach may reduce overdiagnosis by distinguishing very low‑risk disease that is unlikely to cause harm.

PRIMARY2 reported that the scan identified patients who either had no cancer or whose disease was so low‑risk or slow‑growing that biopsy was unnecessary. Patients with a positive PSMA PET/CT underwent biopsy, which could be targeted to suspicious areas defined by the scan to minimize complications and improve accuracy. Across the cohort, this strategy halved the number of biopsies without missing harmful cancers.

“PSMA PET/CT scanning makes prostate cancer cells light up in a remarkable way, particularly in more aggressive cancers. It's rare to see such strong imaging that could be so powerful in the clinic. Incorporating this testing into clinical care could help to address the major challenge of prostate cancer overdiagnosis, which leads to at best unnecessary and at worst harmful treatment for cancers that would never cause any harm,” said Dr. James Buteau, nuclear medicine physician at Peter MacCallum Cancer Center.

“This well-conducted trial shows that incorporating PSMA PET/CT in men with low or intermediate risk lesions—defined by MRI as PI-RADS 2 or 3—significantly reduced the number of unnecessary biopsies and the diagnosis of clinically insignificant prostate cancer. Importantly, this didn’t compromise the detection of clinically significant disease. These results support consideration of PSMA PET/CT in the diagnostic work-up of appropriately selected patients. I congratulate the investigators on their study,” said Professor Dr. Derya Tilki, member of the EAU Scientific Congress Office and senior consultant urologist at Martini-Klinik Prostate Cancer Center, Germany.

Related Links
Peter MacCallum Cancer Center in Melbourne
St Vincent's Hospital in Sydney