PSMA PET found more significant cancer than MRI-targeted biopsy in PI-RADS 3 lesions

Design

Single-centre prospective paired diagnostic study

Population

66 biopsy-eligible men with a PI-RADS 3 lesion and a high-risk feature

Primary outcome

Per-patient detection of clinically significant cancer

Effect

15% PSMA-targeted vs 6% MRI-targeted (difference 9%, 95% CI 2–18%); NPV 100%

PANDORA was a single-centre prospective paired diagnostic study. Men eligible for biopsy with an equivocal PI-RADS 3 lesion and at least one high-risk feature had PSMA PET/MRI before transperineal biopsy, then MRI-targeted, PSMA-targeted (when positive) and systematic cores.

Of 66 men who completed the protocol, PSMA PET was positive in 21 (32%). PSMA-targeted biopsy found clinically significant cancer in 10 (15%) against 4 (6%) for MRI-targeted biopsy (difference 9%, 95% CI 2% to 18%). PSMA PET had 100% sensitivity and negative predictive value in this group: none of the 45 men with a negative scan had significant cancer.

PI-RADS 3 is the commonest grey zone in the MRI pathway, and most biopsies of these lesions find nothing significant. A test that safely avoids two in three of them would be valuable. But 66 men from one centre, with a single PSMA tracer, is not enough to defer biopsy on a negative scan yet, as the authors themselves say.

• Consider PSMA PET as a problem-solving test for PI-RADS 3 lesions where available, within a study or local protocol.
• A positive PSMA PET gives a target worth sampling alongside MRI-targeted cores.
• Do not yet defer biopsy on a negative PSMA PET alone; the negative predictive value needs larger studies.
• Continue to use PSA density and clinical risk to decide on biopsy for PI-RADS 3 lesions.

Why it matters

It addresses the commonest uncertain result in the MRI-first prostate pathway.

Don't overread it

A 66-man single-centre study; it does not show that deferring biopsy after a negative PSMA PET is safe.

The statistics, in plain English

A 100% negative predictive value means none of the 45 men with a negative scan had significant cancer. With only 45 men, the true value could be lower. The 9% difference in detection has a wide interval (2% to 18%), reflecting the small sample.

Read the rest in the app

You have read your two free briefings this month. The app carries all 27 specialties, every morning, free — and this finding is waiting in it.

Get Daily Doctor — free

Scan to keep reading on your phone. No account needed to start.