EAU 2023: PSMA-PET in Local Evaluation of the Prostate for Active Surveillance? Yes

(UroToday.com) The 2023 European Association of Urology (EAU) annual congress held in Milan, Italy between March 10th and 13th, 2023 was host to a plenary session addressing the “right management” of prostate cancer patients in the early detection and active surveillance settings. Dr. Renu Eapen was tasked with debating in favor of PSMA-PET/CT having a role in the local evaluation of the prostate for active surveillance patients.

Active surveillance is an established standard of care for patients with low-risk prostate cancer. Conversely, “intermediate” risk prostate cancer is a heterogenous disease state, for which active surveillance may be an appropriate management strategy for a subset of such patients. Given the increased popularity of active surveillance for this cohort of patients, imaging-based tools for their stratification have emerged.

The PRIMARY trial was a prospective multicenter phase II imaging trial that enrolled men with suspected prostate cancer (PCa), no prior biopsy, and a recent mpMRI examination within 6 months, and for whom prostate biopsy was planned. In total, 291 men underwent an mpMRI, 68Ga-PSMA PET/CT, and systematic biopsy with or without targeted biopsy.


A combined mpRMI + PSMA-PET/CT approach improved the sensitivity from 83% with MRI alone to 97% when combined (NPV: 72% to 91%), at the expense of decreased specificity (53% reduced to 40%). Significantly, a combination approach reduced the false negative rate for detection of clinically significant prostate cancer (csPCa) from 17% to 3.1%.1


Interestingly, there was a direct correlation between the SUVmax level and increased/worsening ISUP grade group disease. The probability of csPCa increased exponentially as the SUVmax increased from 2.5 to 10, with the probability of csPCa leveling off at 1.0 for lesions/patients with SUVmax of 10 or greater.


Among patients with an MRI positive lesion (PIRADS 4/5) and a PSMA positive scan with an SUVmax of >9, the PPV for csPCa was 100%. A similar PPV of 100% for csPCa was observed when patients had any MRI (PIRADS 2/3) and a PSMA positive scan with an SUVmax of >12.

Can we combine the SUVmax score with other PET-generated parameters to produce a scoring system that predicts the likelihood of csPCa? The PRIMARY score was derived based on the intensity and pattern of uptake with a 5-point Likert scale analogous to that of the PIRADS for mpMRI.2



Similar to the PIRADSv2 scoring system, patients with PRIMARY score lesions of 3 or worse are generally considered to have “positive” lesions:
  • SCORE 3: Focal transition zone uptake
  • SCORE 4: Focal peripheral zone uptake
  • SCORE 5L SUVmax >12
As demonstrated in the table below, as PRIMARY score increases, the probability of detecting csPCa within such lesions correspondingly increases with PRIMARY score 5 lesions having a 100% PPV for csPCa.

Dr. Eapen next highlighted a case study of a patient with GG2 disease and 2 lesions with PRIMARY scores of 1 and 2, respectively.


She contrasted that with a second scenario of a similar patient with GG2 disease, but now with 2 lesions of PRIMARY scores 4 and 5, respectively. In her practice, the first patients would be a suitable candidate for active surveillance given that his risk of high-grade disease is considerably low if re-biopsied. Conversely, given the location/intensity of tracer uptake in the 2nd patent’s PSMA-PET/CT, there would be considerable concern for underlying high-grade disease, and this patient would thus be likely offered radical treatment.


Presented by: Renu Eapen, MBBS, FRACS (Urol), Department of Urology, Peter MacCallum Cancer Centre, Melbourne, Australia

Written by: Rashid K. Sayyid, MD, MSc – Society of Urologic Oncology (SUO) Clinical Fellow at The University of Toronto, @rksayyid on Twitter during the 2023 European Association of Urology (EAU) 38th annual congress held in Milan, Italy between March 10-13, 2023


  1. Emmett et al. The Additive Diagnostic Value of Prostate-specific Membrane Antigen Positron Emission Tomography Computed Tomography to Multiparametric Magnetic Resonance Imaging Triage in the Diagnosis of Prostate Cancer (PRIMARY): A Prospective Multicentre Study. Eur Urol, 2021. 80(6):682-689.
  2. Emmett et al. The PRIMARY Score: Using Intraprostatic 68Ga-PSMA PET/CT Patterns to Optimize Prostate Cancer Diagnosis. J Nucl Med, 2022. 63(11):1644-1650.