Validation of an MRI-based prostate cancer prebiopsy Gleason score predictive nomogram

Area of Science:

• Oncology
• Radiology
• Urology

Background:

• Gleason score grading is crucial for prostate cancer (PCa) risk stratification and management.
• Accurate prediction of biopsy Gleason scores (bGS) is essential for optimal patient care.

Purpose of the Study:

• To derive and validate a predictive nomogram for biopsy Gleason scores (bGS) using prostate multiparametric magnetic resonance imaging (MP-MRI) and clinical data.
• To assess the nomogram's accuracy in predicting PCa and clinically significant PCa.

Main Methods:

• A predictive nomogram was developed using data from 143 men who underwent MP-MRI before biopsy.
• The nomogram was validated on an independent cohort of 235 men from another institution.
• Prostate-specific antigen (PSA) density, number of screen-positive lesions, and MRI suspicion were key predictors.

Main Results:

• The nomogram predicted the correct bGS in 61% of the original cohort and 51% of the validation cohort.
• It correctly identified any PCa versus non-PCa in 63% of cases and clinically significant PCa (Gleason score ≥ 7) in 69% of cases.
• The negative predictive value for clinically significant PCa was 74% in the validation group.

Conclusions:

• A prebiopsy nomogram incorporating PSA and MRI findings can effectively predict biopsy Gleason scores.
• The nomogram demonstrates potential for identifying men who may not need biopsies, impacting PCa risk stratification.
• This study highlights the feasibility and utility of prebiopsy prediction of bGS.