title: Apparent diffusion coefficient value and ratio as noninvasive potential biomarkers to predict prostate cancer grading: comparison with prostate biopsy and radical prostatectomy specimen.
abstract: OBJECTIVE. The purpose of this study is to test the association between diffusion-weighted MRI and prostate cancer Gleason score at both biopsy and final pathologic analysis after radical prostatectomy. SUBJECTS AND METHODS. Patients with prostate cancer (n = 72) underwent diffusion-weighted MRI (b values, 0, 800, and 1600 s/mm(2)) with an endorectal coil. Apparent diffusion coefficient (ADC) and ADC ratio were obtained in normal and pathologic tissue and were correlated with transrectal ultrasound-guided biopsy (n = 72) and histopathologic (n = 39) Gleason scores using the ANOVA test. ADC accuracy was estimated using ROC curves. RESULTS. Lesions suspicious for prostate cancer were detected in 65 patients. The mean ADC was 1.47 and 0.87 × 10(-3) mm(2)/s for normal and pathologic tissue, respectively (p < 0.001). When we divided the population into four groups (normal tissue and biopsy Gleason scores of 6, 7, and 8-10), then the mean ADC value was 1.47, 0.96, 0.80, and 0.78 × 10(-3) mm(2)/s, respectively (p < 0.001). The ADC ratio decreased along with an increase in biopsy Gleason score (66.9%, 56.7%, and 51.5% for Gleason scores of 6, 7 and 8-10, respectively) (ANOVA, p = 0.003) and pathologic Gleason score (ANOVA, p < 0.001). ROC curves had an AUC of 0.94 and 0.86 for ADC and ADC ratio, respectively (p = 0.012 and 0.042, respectively). CONCLUSION. Decreasing ADC values may represent a strong risk factor of harboring a poorly differentiated prostate cancer, independently of biopsy characteristics.
authors.affiliation: 1 Department of Radiology and Center for Experimental Imaging, San Raffaele Scientific Institute, Vita-Salute University, Olgettina 60, Milan 20132, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: De Cobelli
authors.forename: Silvia
authors.initials: S
authors.lastname: Ravelli
authors.forename: Antonio
authors.initials: A
authors.lastname: Esposito
authors.forename: Francesco
authors.initials: F
authors.lastname: Giganti
authors.forename: Andrea
authors.initials: A
authors.lastname: Gallina
authors.forename: Francesco
authors.initials: F
authors.lastname: Montorsi
authors.forename: Alessandro
authors.initials: A
authors.lastname: Del Maschio
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D038524:Diffusion Magnetic Resonance Imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011467:Prostate / Q000473:pathology; D011468:Prostatectomy / Q000379:methods; D011471:Prostatic Neoplasms / Q000473:pathology* / Q000601:surgery*
keywords: Gleason score; apparent diffusion coefficient; apparent diffusion coefficient ratio; diffusion-weighted imaging; prostate cancer