Development and validation of a multimodal artificial intelligence-based model for predicting post-prostatectomy...

Prostate cancer (PCa) is the second most common cancer and cause of cancer deaths among American men. Existing risk prediction methods have limited accuracy and reproducibility, resulting in difficulty in predicting treatment outcomes. We demonstrate the development and external validation of an automated multimodal artificial intelligence (AI) algorithm using biparametric magnetic resonance imaging (bpMRI) and clinical covariates for predicting biochemical recurrence (BCR) after radical prostatectomy (RP) in patients with PCa.

The development cohort included 80% of patients from center 1 (n = 240) who underwent prostate MRI prior to RP between January 2008 and December 2018, with a minimum of 2 years of follow-up after RP. The test cohort included the remaining 20% of center 1 patients (n = 71) and an external validation cohort from center 2 (n = 168). Center 2 patients included those who underwent prostate MRI and RP between January 2015 and January 2024, with a minimum of 2 years of follow-up. Clinical comparisons were made using the Cancer of the Prostate Risk Assessment Postsurgical (center 1) and International Society of Urological Pathology Gleason Grade Group (ISUP GGG) scoring systems from post-RP pathology (center 2). The models developed were as follows: clinical (M0), automated clinical (M1), radiomics (M2), and a multimodal model (M3). Clinical variables (M0) included prostate-specific antigen (PSA), age, primary Gleason, and ISUP GGG. Automated clinical variables (M1 and M3) included PSA and age. Radiomic features (M2 and M3) were extracted from bpMRI using a lesion detection AI model. Accuracy, sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) were calculated, and log-rank tests compared BCR-free survival to assess the models' ability to discriminate relative to clinical standards. Intermediate-risk groups were also assessed.

The multimodal model (M3) had the highest AUC across test sets (combined: 0.71; center 1: 0.70; center 2: 0.75). This was the only model that significantly differentiated BCR-free survival outcomes in intermediate-risk groups across both centers (P < 0.05).

This automated multimodal model leveraging radiomics and clinical covariates can predict BCR after RP, approaching clinical gold standards, and may enhance imaging-based prognostication following further validation.

Given that this model demonstrated the potential to outperform pre-surgical and post-surgical clinical gold standards in an external cohort's intermediate-risk patient subgroup (for whom it is more challenging to predict disease trajectory), this model may contribute to enhanced personalized care in PCa after further validation.