Prostatic artery embolization and imaging-based biomarkers: current tools in monitoring treatment response and emerging strategies

Prostatic artery embolization (PAE) is a safe and effective minimally invasive treatment for lower urinary tract symptoms (LUTS) attributed to benign prostatic hyperplasia (BPH), including in patients with large prostates, who are poor surgical candidates or wish to avoid the morbidity of conventional surgery or transurethral interventions. As PAE becomes more widely adopted for BPH-related LUTS, objective measures of assessing treatment response are needed beyond symptom-based tools such as the International Prostate Symptom Score (IPSS) and Quality-of-Life (QoL) index. Imaging biomarkers complement these subjective endpoints by quantifying structural, functional, ischemic, and microstructural changes within the prostate before and after embolization. This review summarizes the principal imaging modalities used for biomarker assessment in PAE, with emphasis on ultrasound, magnetic resonance imaging (MRI), and computed tomography (CT) scans, and examines the current literature on imaging biomarkers of treatment response. Volumetric biomarkers, including whole prostate volume, central gland volume, and zonal volumetry index, provide quantitative assessment of gland reduction and may help predict clinical improvement, with zonal parameters showing stronger associations with symptomatic outcomes than whole-gland measurements alone. Functional biomarkers such as postvoid residual volume offer objective evaluation of bladder emptying alongside volumetric assessment, whereas ischemia-based biomarkers derived from contrast-enhanced MRI directly reflect embolization-induced devascularization. Diffusion-weighted imaging and apparent diffusion coefficient mapping provide additional information regarding post-embolization tissue remodeling, with b-value selection influencing early infarct detection. Emerging tools, including ultrasound elastography, radiomics, and artificial intelligence-assisted image analysis, may further refine patient selection, standardize response assessment, and improve predictive modeling, though prospective PAE-specific validation remains needed. Imaging biomarkers provide a more objective framework for evaluating PAE treatment response, with the potential to standardize outcome reporting, facilitate earlier identification of treatment success or failure, and guide biomarker-driven clinical decision-making. Prospective validation in larger PAE-specific cohorts remains essential before broader clinical adoption.