MRI radiomics predicting cribriform growth informs active surveillance decision in intermediate-risk prostate cancer

Objective:

Accurate exclusion of cribriform growth (GP4Crib+), an adverse histologic feature in prostate cancer, remains a challenge in selecting intermediate-risk patients for active surveillance (AS). This study evaluates whether an MRI-based radiomics model predicting GP4Crib+ can support AS inclusion decisions under the assumption that intermediate-risk men without GP4Crib+ could be safely managed with AS. 

Materials and methods: 

This single-center retrospective study was approved by the institutional review board (IRBd21-108) and included men with Cambridge Prognostic Group (CPG) -1, CPG-2, or CPG-3 (Gleason grade (GG) 2) prostate cancer who underwent MRI and radical prostatectomy. In this cohort, a previously trained radiomics model was applied across the whole prostate to generate voxel-wise GP4Crib+ probability maps, to ultimately identify men with GP4Crib. This model was tested in two scenarios: (1) CPG-1+2, and (2) CPG-1+2+3(GG2) patients on biopsy. The reference scenario was CPG-1 men to AS (guideline recommendations). 

Results: 

We included 127 patients (median age 66 years, interquartile range 47‒78). Standalone radiomics performance was moderate (area under the receiver operating characteristic curve (AUROC): 0.68 overall; 0.60 for CPG-2; and 0.70 for CPG-3(GG2)). At a 0.60 probability threshold, the model reduced overtreatment by 9% in CPG-1 + 2 men (with 1% increase in undertreatment). In CPG-1+2+3(GG2) men, the model reduced overtreatment by 8%, maintaining low undertreatment (3%). Most false negatives involved smaller than 1.5-mm cribriform foci. 

Conclusion: 

Our MRI-based GP4Crib+ radiomics model is able to support AS decisions in men with CPG-1+2+3(GG2). Despite modest standalone diagnostic performance, its integration into the clinical work-up may help safely expand AS selection to intermediate-risk men, ultimately reducing overtreatment. Relevance statement: MRI-based radiomics may support noninvasive exclusion of cribriform growth to guide active surveillance eligibility in intermediate-risk prostate cancer, enabling safer management decisions and reducing unnecessary treatment. Key Points: Prostate cancer cribriform growth is difficult to detect but crucial for treatment decisions. MRI radiomics helps exclude cribriform growth in intermediate-risk prostate cancer patients. Radiomics-informed decisions reduced overtreatment under structured AS scenarios.