EAU 2011 - A negative multi-parametric MRI can rule out up to 97% of clinically significant prostate cancer - Session Highlights

VIENNA, AUSTRIA (UroToday.com) - The objective of this study was to evaluate a role for multi-parametric MRI (mp-MRI) in ruling-out clinically significant prostate cancer.

The impetus for the study was to improve upon previous studies that used whole-mount specimens from men with a diagnosis of prostate cancer on TRUS biopsy as the reference standard, incorporating a work-up bias. This study reported on the performance characteristics of mp-MRI using template prostate mapping (TPM) as the reference standard.

Mp-MRI (T1/T2, dynamic contrast enhancement and diffusion weighting, 1.5Tesla, pelvic phased array) was performed before TPM in men with an elevated PSA (n=65), of whom 16 had no previous cancer diagnosis, and 49 had proven cancer on previous TRUS biopsy. Each mp-MRI was interpreted by three uro-radiology experts (R1-R3). Each prostate was divided into 4 regions of interest (ROI) and a score of 1 to 5 assigned to each ROI (1 - ‘no cancer’, 5 - ‘highly suspicious’). TPM was performed under general anesthesia with 5mm-spaced sampling using a brachytherapy template grid. Analysis was carried out for all cancer on TPM. Two definitions of clinical significance were applied: Definition 1) Gleason grade ≥4+3 and/or ≥6mm cancer core length (CCL) Definition 2) Gleason grade ≥3+4 and/or ≥4mm CCL.

Sixty-five consecutive men (260 ROIs) with a mean age 62 years and mean PSA 8.2ug/L (range 2.1–43) were evaluated. 130/260 (50%) of ROIs were positive for cancer on TPM. By definition 1 and 2, 38/260 (15%) and 69/260 (27%) had positive ROIs, respectively. Accuracy using area under receiver-operator characteristic curve (AUC) improved from 0.66 – 0.70 for all cancer to 0.71-0.85 and 0.72-0.83 for clinically significant cancer by definition 1 and 2. The negative predictive value of mp-MRI was 0.93-0.97 for definition 1 cancer and 0.85-0.90 for definition 2 cancers, respectively.

The investigators suggest that this finding could be used to address the over-diagnosis burden from PSA screening by using mp-MRI as a triage test to identify men who could avoid a prostate biopsy. However, cost-analysis of this approach was not included.


Presented by Nimalan Arumainayagam, et al. at the 26th Annual European Association of Urology (EAU) Congress - March 18 - 21, 2011 - Austria Centre Vienna, Vienna, Austria


The opinions expressed in this article are those of the UroToday.com Contributing Medical Editor and do not necessarily reflect the viewpoints of the European Association of Urology (EAU)


View EAU 2011 Annual Meeting Coverage