Prostagram MRI in a Screening Population: PI-RADS or Likert?

The IP1-PROSTAGRAM study highlighted the potential of short biparametric "Prostagram" magnetic resonance imaging (bpMRI) scanning in screening for prostate cancer. We aimed to compare biopsy recommendation rates and accuracy of PI-RADSv2 with the Likert scale for detection of clinically significant and insignificant prostate cancer in men screened within IP1-PROSTAGRAM.

Men aged 50-69 years were screened with Prostagram MRI. Scans were prospectively reported using both PI-RADSv2 (excluding dynamic contrast-enhanced sequence score) and 5-point Likert scores by expert uro-radiologists. Systematic and targeted transperineal biopsy was recommended if the scan was scored ≥3, based on either reporting system. The proportion of patients recommended for biopsy and detection rates for grade groups (GG) 1 and ≥2 were compared. Receiver operating characteristic (ROC) analysis was performed to compare performance.

406 men underwent Prostagram MRI. Median age and PSA were 57 years (IQR 53-61) and 0.91 ng/mL (0.56-1.74), respectively. At MRI score ≥3, more patients were recommended for biopsy based on Likert criteria (94/406, 23% [95% CI 19.2-27.6%]) compared to PI-RADSv2 (72/406, 18% [14.2-21.9%]; p=0.03). For scores ≥4, PI-RADSv2 and Likert scales led to 43/406 (11%, 7.9%-14.1%) and 35/406 (9%, 6.2-11.9%) men recommended for biopsy (p=0.40). For GG≥2 detection, PIRADSv2 and Likert detected 22% (11.4-30.8%, 14/72) and 16% (9.5-25.3%, 15/94), respectively (p=0.56). For GG1 cancers detection these were 11% (4.3-19.6%, 7/72) vs 11% (4.7-17.8%, 9/94) (p=1.00). The accuracy of PI-RADS and Likert scale was similar (AUROC 0.64 vs 0.65, p=0.95).

In reporting non-contrast-enhanced Prostagram MRI in a screening population, the PI-RADSv2 and Likert scoring systems were equally accurate; however, Likert scale use led to a more men undergoing biopsy without a subsequent increase in significant cancer detection rates. To improve reporting of Prostagram MRI, either the PI-RADS or a modified Likert scale or a standalone scoring system should be developed.

BJU international. 2023 Aug 17 [Epub ahead of print]

Nikhil Mayor, David Eldred-Evans, Henry Tam, Heminder Sokhi, Anwar R Padhani, Martin J Connor, Derek Price, Martin Gammon, Natalia Klimowska-Nassar, Paula Burak, Emily Day, Mathias Winkler, Francesca Fiorentino, Taimur Shah, Hashim Uddin Ahmed

Imperial Prostate, Division of Surgery, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, UK., Department of Radiology, Imperial College Healthcare NHS Trust, London, UK., Department of Radiology, The Hillingdon Hospitals NHS Foundation Trust, London, UK., Paul Strickland Scanner Centre, Mount Vernon Hospital, Middlesex, UK., Public and patient representative, Solihull, UK., Public and patient representative, Dorking, Surrey, UK., Imperial Clinical Trials Unit, Imperial College London, London, UK.