Do we still need dynamic contrast-enhanced MRI for the assessment of extracapsular extension of prostate cancer?
Number:27ESURABS0012
Type:Scientific Electronic Presentation
Authors: Lorenzo Vassallo, Mirella Fasciano, Andrea Cerutti, Carla Angela Zavattero
Keywords:MRI - Prostate Cancer - Extracapsular - Contrast
SECTIONS
Objectives

Multiparametric magnetic resonance imaging (mpMRI) has emerged as an important tool in the early diagnosis of prostate cancer (PCa) and is particularly helpful in the detection, local staging, and estimation of the aggressiveness of prostate cancer lesions. mpMRI is currently recognized as the best imaging method for assessing prostate cancer. According to the recommendations of the Prostate Imaging Reporting and Data System version 2 (PI-RADS V2), mpMRI includes T1- and T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI) and dynamic contrast-enhanced (DCE) MRI. 

In the last years biparametric Magnetic Resonance Imaging (bpMRI) of the prostate combining both morphologic T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI) is emerging as an alternative to mpMRI to detect, to localize and to guide prostatic targeted biopsy in patients with suspicious...

...read more


Material and methods

We retrospectively analyzed 86 consecutive patients who underwent 1.5T mp-MRI of the prostate followed by radical prostatectomy between January 2017 and July 2020. 

Patients with severe artefacts on DWI were excluded from the study.

Images were acquired with a 1.5-T scanner (Optima MR450w, GE Healthcare, Milwakee, Illinois, USA) using both 32- channel phased-array and air-inflated endorectal coils (Medrad, Indianola, Pa). Axial T2-weighted (T2w), diffusion-weighted (DW) and dynamic contrast-enhanced (DCE) sequences were obtained as detailed in Table 1. The DCE sequence was triggered to start simultaneously with the power injection of 0.1 mmol/kg gadobutrol (Gadovist, Bayer Schering, Berlin, Germany) through a peripheral line at 0.7 ml/s, followed by infusion of 20 cc normal saline at the same rate. The average time to complete the whole MRI exam was 40 min....

...read more


Results

Mean participants age was 65.7 (range years 55.2 - 78.5), median prostate-specific antigen was 7.4 ng/mL (range, 3.2-21.9 ng/mL) and median prostate volume was 53.1 ml (range, 36.5 - 80.4 mL).

At histopathological analysis PCa was considered EPE- in 36 patients and had EPE+ in 50 (Figure 1).
Sensitivity, specificity, accuracy, positive predictive value and negative predictive value of bpMRI for EPE were 84%, 88.9%, 91.3%, 80% and 86% while for mpMRI were 88%, 86.1%, 89.7%, 83.8% and 87.2% (Figure 2, 3 and 4).
Interprotocol agreement between the two protocols was excellent (k=0.9).
In eight cases EPE- was uncorrectly planned by bpMRI (and in six cases also by mpMRI), at histology in all the cases pathology detected only the presence of microscopic EPE. The two patients with EPE+ detected by mpMRI and not by bpMRI were PCa of the transitional zone with anterior...

...read more

Figure 1. Statistical analysis.
Figure 2. Diagnostic performance of bpMRI in EPE detection.

Conclusions

Our study showed that bpMRI in predicting extracapsular extension of PCa has more than acceptable accuracy compared to mpMRI (only slightly lower than mpMRI) and could represent a reliable tool in pre-surgical setting.

In particular in patients with a lesion in the peripheral zone the use of DCE imaging provides no benefit for the discrimination of T2/T3 stage. However, in lesions localized in the transitional zone the implementation of DCE sequence could increase the ability in the detection of microscopic EPE.

In addition, bpMRI has the advantages of reducing cost. time and contrast exposure by eliminating the DCE phase of mpMRI.

Our study has some limitations. First, it was a retrospective, single centre study performed on a relatively small cohort. In addition MRI examinations were analyzed bt a single reader, who however had over than 7 years of...

...read more