Value of endorectal magnetic resonance imaging at 3T for the local staging of prostate cancer

Abstract

Purpose: To assess the accuracy of endorectal 3 T magnetic resonance imaging (MRI) in detecting extracapsular extension (ECE) and seminal vesicle invasion (SVI) of prostate cancer (PCa).

Materials and methods: 38 consecutive patients with biopsy-proven PCa underwent multiparametric endorectal MRI at 3 T prior to prostatectomy. Two readers (A with nine years of experience and B with four) used established criteria for ECE and SVI to diagnose the extent of local disease in six regions (apical, dorsolateral, basal; left and right each) with the highest chance of ECE. The standard of reference was provided by intraoperative frozen section analysis and prostatectomy specimens.

Results: Histopathology revealed ECE in 15 of the 222 regions (10 of 37 patients) and SVI in 8 of 74 potential regions (5 of 37 patients). The sensitivity, specificity, and accuracy in detecting ECE for reader A/B were 93%/67%, 92%/95% and 92%/93% per region and 90%/80%, 74%/82% and 78%/81% per patient, respectively. The corresponding values for the detection of SVI were 80%/100%, 96%/99% and 95%/97%, respectively.

Conclusion: Endorectal 3 T MRI is a highly reliable noninvasive technique for the local staging of PCa.

Key points: ► Endorectal 3 T MRI provided high accuracy for the local staging of prostate cancer. ► The sensitivity in detecting extracapsular tumor growth per patient was 80% or higher. ► The specificity in detecting extracapsular extension (pT3 stage) was good.