Introduction

Dynamic contrast-enhanced imaging (DCE) is recommended by Prostate Imaging - Reporting And Data System (PI-RADS) guidelines in addition to the combination of T2-weighted imaging (T2W) and diffusion-weighted imaging (DWI) for prostate cancer (PCa) detection, but its usefulness is not well-established. We compared the performance of biparametric (T2W+DWI) and triparametric (T2W+DWI+DCE) MRI, in the diagnosis of the index lesion.

Methods

Fifty-seven patients (who underwent preoperative mpMRI and radical prostatectomy) and 23 controls (examined by mpMRI, with at least a 2-year follow-up excluding PCa) were retrospectively analysed. Biparametric MRI and triparametric MRI (the latter according to PI-RADSv2) were reviewed by 5 independent radiology residents, allowing a 4-week interval between the two sessions. Each reader had an 8 months dedicated MRI experience and was blinded to clinical and pathological data. A senior consultant uro-pathologist reviewed whole-mount sections (according to 2014 ISUP protocol), providing the reference standard for comparing diagnostic accuracy. The index lesion was defined as the largest PCa focus identified at the final pathology.

Results

No statistically significant difference in index lesion detection was observed among bi- and triparametric MRI, in a pooled analysis of the 5 readers. Sensitivity was 72% and 81% respectively (p=0.08); specificity was 78% and 79% (p=0.92); accuracy was 74% and 81% (p=0.12; Figure 1). The larger lesion had also the higher Gleason score in 53/57 patients (92,9%). Bi- triparametric MRI did not differ significantly in measuring lesion diameter (p=0.54), although histologic value was significantly higher than measures of both imaging protocols (+54% on average, p=0.01).

Conclusions

No significant difference in detecting and measuring prostate cancer index lesion was observed by adding DCE sequences to T2W and DWI, among MRI readers with intermediate experience. The sole use of biparametric prostate MRI can provide a good diagnostic accuracy on index lesions.

Funding

None