The value of ADC, T2 signal intensity, and a combination of both parameters to assess Gleason score and primary Gleason grades in patients with known prostate cancer

Abstract

Background: The ability to non-invasively analyze tumor aggressiveness is an important predictor for individual treatment stratification and patient outcome in prostate cancer (PCA). Purpose: To evaluate: (i) whether apparent diffusion coefficient (ADC), the T2 signal intensity (SI), and a combination of both parameters allow for an improved discrimination of Gleason Score (GS) !7 (intermediate and high risk) and GS <7 (low risk) in PCA; and (ii) whether ADC may distinguish between 3 þ 4 and 4 þ 3 PCA (primary Gleason grades [pGG]). Material and Methods: Prostatectomy specimens of 66 patients (mean age, 63 AE 5.6 years; 104 PCA foci) with a preceding multiparametric 1.5 T endorectal coil magnetic resonance imaging (MRI) were included. ADC (b values ¼ 0, 100, 400, 800 s/mm 2 ), standardized T2 (T2s), and the ADC/T2s ratio were tested for correlation with GS applying multivariate analysis. ADC cutoff values were calculated for prediction of GS and pGG, and logarithm of the odds (LOGIT) was used to express the probability for GS and pGG. Diagnostic accuracy was assessed by ROC analysis. Results: We found an almost linear negative relationship of ADC for GS !7 (P ¼ 0.002). The effect of ADC for GS !7 (adjusted odds ratio ¼ 0.995) was almost identical for peripheral and transition zone PCA (P ¼ 0.013 and P < 0.001, respectively). ADC showed an AUC of 78.9% for discrimination between GS <7 and GS !7. An ADC cutoff of <1.005 Â 10 À3 mm 2 /s indicated a GS !7 (90.5% sensitivity, 62.5% specificity). Within the group of GS ¼ 7 PCA, an ADC > 0.762 Â 10 À3 mm 2 /s indicated a pGG of 3 (AUC ¼ 69.6%). Conclusion: T2s and the ADC/T2s ratio do not provide additional information regarding prediction of GS. ADC values have a good discriminatory power to distinguish tumors with GS !7 from GS <7 and to predict pGG in GS ¼ 7 PCA.

Predictive role of PI-RADSv2 and ADC parameters in differentiating Gleason pattern 3 + 4 and 4 + 3 prostate cancer

“…The role of ADC metrics in differentiating GP 3+4 vs 4+3 PCa have been addressed by few studies [19,20,28]. A study on 57 GS=7 PCa showed that ADC/T2 ratio, defined as the ratio of ADC values and of the signal intensity of the tumor measured respectively on ADC maps and T2WI, had a sensitivity of 77.5% and a specificity of 64.7% in discriminating GP 3+4 from 4+3 PCa [29].…”

Computer-aided Detection of Prostate Cancer with MRI

“…T2 values of histologically proven malignant tumor areas were significantly lower than the suspicious lesions but nonmalignant lesions or normal areas [26]. The use of quantitative T2 measurement improves the specificity and/or sensitivity of prostate cancer detection [27] and aggressiveness assessment [28, 29]. There is a potential benefit of incorporating quantitative T2 values into CADx systems.…”

“…The Gleason grading system is a fundamental indicator of the aggressive nature of prostate cancer. Studies found that ADC image features correlate with Gleason scores [27, 28, 46, 154–156]. A study by Yamamura et al found a highly significant negative correlation between ADC-value and the Gleason score, while MRS did not show a significant correlation [157].…”

Prostate cancer detection using quantitative T2 and T2‐weighted imaging: The effects of 5‐alpha‐reductase inhibitors in men on active surveillance

“…1 Today, mpMRI plays a pivotal role in the diagnosis and risk stratification of men with prostate cancer. 3,4 T 2 -WI generates a high signal-to-noise ratio (SNR) and confers high spatial resolution. 3,4 T 2 -WI generates a high signal-to-noise ratio (SNR) and confers high spatial resolution.…”