Login to Access Video or Poster Abstract: MP20-11
Sources of Funding: none

Introduction

Clinical assessment of extracapsular extension (ECE) in prostate cancer may have a significant impact on treatment decision and/or surgical planning. Multi-parametric magnetic resonance imaging (MP-MRI) has emerged as a potential tool to predict the presence of ECE with variable results. Our objective was to define the accuracy of MP-MRI for detection of ECE in relation to its radial and circumferential extent.

Methods

We prospectively enrolled 70 patients to undergo prostate MP-MRI prior to radical prostatectomy. All MRIs were performed with a 3T scanner using an endorectal coil and T2, diffusion weighted imaging (DWI), and dynamic contrast enhanced (DCE) sequences were used. An expert genitourinary radiologist reviewed each MP-MRI and assigned a score of diagnostic certainty between 1-3 (1-absent, 2-suspicious, 3-definite) regarding the presence of ECE on each sequence (T2, DWI, and DCE, in that order). Prostatectomy whole-mount specimens were reviewed by a genitourinary pathologist and the radial and circumferential extent of ECE was measured. The accuracy of each MRI sequence was determined, as well as its association between circumferential and radial extent of ECE.

Results

70 enrolled patients underwent MP-MRI of the prostate followed by radical prostatectomy. Mean preoperative PSA was 8.4 ng/dL and 50 patients (71%) had Gleason 7 or higher on final pathology. Sensitivity and specificity of MP-MRI for suspicious or definite ECE was 92.9% and 63.4%, respectively. Sensitivity and specificity of definite ECE was 78.6% and 68.3%. Area under the curve for T2, DWI, and ECE sequences was 0.79, 0.76, 0.78, respectively. Radial extent of ECE was not associated with its detection on any sequences. Circumferential extent of ECE was positively associated with suspicious or definite detection on DCE imaging (p=0.04).

Conclusions

Preoperative 3T MP-MRI of the prostate with endorectal coil interpreted by a 3-point scale is highly sensitive for predicting ECE. The radial extent of ECE is not associated with its detection on MP-MRI, however the circumferential extent is associated with its detection on DCE sequences.

Funding

none