Comparison of real-time elastography and multiparametric MRI for prostate cancer detection: a whole-mount step-section analysis.

OBJECTIVE

The purpose of this study was to compare prostate cancer detection rate of real-time elastography (RTE) with that of multiparametric MRI to evaluate the advantages and disadvantages of the two methods.

SUBJECTS AND METHODS

Thirty-nine patients with biopsy-proven prostate cancer underwent both RTE and multiparametric MRI to localize prostate cancer before radical prostatectomy. RTE was performed to assess prostate tissue elasticity, and hard lesions were considered suspicious for prostate cancer. Multiparametric MRI included T2-weighted MRI, diffusion-weighted MRI (DWI), and contrast-enhanced MRI (CE-MRI) with an endorectal coil at 1.5 T. After radical prostatectomy, whole-mount step sections of the prostate were generated, and the prostate cancer detection rates with both modalities were analyzed for cancer lesions measuring 0.2 cm3 or larger.

RESULTS

Histopathologic examination revealed 61 cancer lesions. RTE depicted 39 of 50 cancer lesions (78.0%) in the peripheral zone and 2 of 11 (18.2%) in the transitional zone. Multiparametric MRI depicted 45 of 50 cancer lesions (90.0%) in the peripheral zone and 8 of 11 (72.7%) in the transitional zone. Significant differences between the two modalities were found for the transitional zone and anterior part in prostates with volumes greater than 40 cm3 (p<0.05). Detection rates for high-risk prostate cancer (Gleason score≥4 and 3) and cancer lesions with volumes greater than 0.5 cm3 were high for both methods (93.8% and 80.5% for RTE, 87.5% and 92.7% for multiparametric MRI). Volumetric measurements of prostate cancer were more reliable with T2-weighted MRI than with RTE (Spearman rank correlation, 0.72 and 0.46).

CONCLUSION

RTE and multiparametric MRI depicted high-risk prostate cancer with high sensitivity. However, multiparametric MRI seems to have advantages in tumor volume assessment and for the detection of prostate cancer in the transitional zone and anterior part within prostates larger than 40 cm3.