Age‐related changes in prostate zonal volumes as measured by high‐resolution magnetic resonance imaging (MRI): a cross‐sectional study in over 500 patients

Abstract

Study Type – Diagnosis (case series) Level of Evidence 4 What's known on the subject? and What does the study add? Benign prostatic hyperplasia is the most common symptomatic disorder of the prostate and its severity varies greatly in the population. Various methods have been used to estimate prostate volumes in the past including the digital rectal examination and ultrasound measurements. High‐resolution T2 weighted MRI can provide accurate measurements of zonal volumes and total volumes, which can be used to better understand the etiology of lower urinary tract symptoms of men. OBJECTIVE • To use ability of magnetic resonance imaging (MRI) to investigate age‐related changes in zonal prostate volumes. PATIENTS AND METHODS • This Institutional Review Board approved, Health Insurance Portability and Accountability Act‐compliant study consisted of 503 patients who underwent 3 T prostate MRI before any treatment for prostate cancer. • Whole prostate (WP) and central gland (CG) volumes were manually contoured on T2‐weighted MRI using a semi‐automated segmentation tool. WP, CG, peripheral zone (PZ) volumes were measured for each patient. • WP, CG, PZ volumes were correlated with age, serum prostate‐specific antigen (PSA) level, International Prostate Symptom Score (IPSS), Sexual Health Inventory for Men (SHIM) scores. RESULTS • Linear regression analysis showed positive correlations between WP, CG volumes and patient age (P < 0.001); there was no correlation between age and PZ volume (P= 0.173). • There was a positive correlation between WP, CG volumes and serum PSA level (P < 0.001), as well as between PZ volume and serum PSA level (P= 0.002). • At logistic regression analysis, IPSS positively correlated with WP, CG volumes (P < 0.001). • SHIM positively correlated with WP (P= 0.015) and CG (P= 0.023) volumes. • As expected, the IPSS of patients with prostate volumes (WP, CG) in first decile for age were significantly lower than those in tenth decile. CONCLUSIONS • Prostate MRI is able to document age‐related changes in prostate zonal volumes. • Changes in WP and CG volumes correlated inversely with changes in lower urinary tract symptoms. • These findings suggest a role for MRI in measuring accurate prostate zonal volumes; have interesting implications for study of age‐related changes in the prostate.