For many men, the fear of prostate cancer does not begin with treatment but with the possibility of undergoing an uncomfortable biopsy. Now a new imaging approach presented at a major European medical congress suggests that thousands of patients may soon be able to avoid that ordeal. Researchers say a specialised scan that makes aggressive prostate cancer cells appear to “glow” on medical images could safely cut the number of unnecessary biopsies by half.

The findings come from the large PRIMARY2 clinical trial, being presented shortly, at the European Association of Urology Congress (EAU26) in London. The study examined whether an advanced scan called PSMA PET/CT could help doctors decide which men truly need a biopsy after an MRI scan gives unclear or reassuring results.

At present, men with suspected prostate cancer usually undergo an MRI scan, which helps doctors identify unusual areas in the prostate gland. However, MRI results are sometimes uncertain. When this happens, especially if there is a strong history of cancer in the family, doctors often suggest a sample to rule out cancer. During a biopsy, a needle is put into the prostate to take tissue samples for testing in the lab. Even though it's popular, the procedure can be painful and come with risks like infection, bleeding, and stress for the patients.

The new study suggests a more precise step between MRI and biopsy. The PSMA PET/CT scan uses a special molecule that attaches to prostate cancer cells. Once attached, the molecule causes those cells to appear as bright spots on the scan image, making them easier for doctors to detect. Importantly, the technique highlights cancers that are more aggressive and likely to require treatment, while also helping identify slow-growing cancers that may never cause harm.

Researchers enrolled 660 men considered at higher risk of prostate cancer, including those with strong family histories, whose MRI scans appeared normal or inconclusive. Participants were randomly assigned either to undergo a standard biopsy or to first receive a PSMA PET/CT scan.

The results were striking. The imaging test was able to identify men who either had no cancer or had very slow-growing disease that would likely never become dangerous. Those patients were able to avoid a biopsy altogether. Overall, using the scan as a second step reduced the number of biopsies by about 50 per cent without missing any clinically significant cancers.

Dr James Buteau, a nuclear medicine physician at Peter MacCallum Cancer Centre in Melbourne who presented the findings, said the imaging technique offers unusually clear results. “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.”

For patients who still required biopsies, the scan also helped guide doctors more accurately. By highlighting suspicious areas inside the prostate, it allowed physicians to target the needle precisely, improving diagnostic accuracy and potentially reducing complications.

Professor Louise Emmett, Director of Theranostics and Nuclear Medicine at St Vincent's Hospital in Sydney, said the method offers reassurance to patients facing uncertainty. “Getting told you have a risk of prostate cancer is a huge cause of anxiety and concern. Our findings show that PSMA PET/CT after MRI offers a 'belt and braces' approach that can determine which people have a clinically significant cancer and which people are at low risk and don’t need a biopsy or further testing. PRIMARY2 is the largest of a series of studies undertaken by this group, exploring whether PSMA PET/CT scanning could improve prostate cancer diagnosis and reduce unnecessary biopsies for patients.”

Independent experts say the results could influence future diagnostic guidelines. Professor Dr Derya Tilki, a member of the EAU Scientific Congress Office and senior consultant urologist at the Martini-Klinik Prostate Cancer Center in Germany, said the study demonstrates the technology’s clinical value. “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.”

The researchers will continue following the participants for two years to confirm long-term outcomes. PSMA PET/CT scans are already widely used in Australia and are becoming more common in Europe and the UK. However, many healthcare systems may not be able to use them more widely because they are too expensive or hard to get. Still, experts think the technology is a big step toward a more accurate and less invasive way to diagnose prostate cancer.