Influence of imaging and histological factors on prostate cancer detection and localisation on multiparametric MRI: a prospective study

Eur Radiol. 2013 Jul;23(7):2019-29. doi: 10.1007/s00330-013-2795-0. Epub 2013 Mar 15.

Abstract

Objectives: To assess factors influencing prostate cancer detection on multiparametric (T2-weighted, diffusion-weighted, and dynamic contrast-enhanced) MRI.

Methods: One hundred and seventy-five patients who underwent radical prostatectomy were included. Pre-operative MRI performed at 1.5 T (n = 71) or 3 T (n = 104), with (n = 58) or without (n = 117) an endorectal coil were independently interpreted by two radiologists. A five-point subjective suspicion score (SSS) was assigned to all focal abnormalities (FAs). MR findings were then compared with whole-mount sections.

Results: Readers identified 192-214/362 cancers, with 130-155 false positives. Detection rates for tumours of <0.5 cc (cm(3)), 0.5-2 cc and >2 cc were 33-45/155 (21-29 %), 15-19/35 (43-54 %) and 8-9/12 (67-75 %) for Gleason ≤6, 17/27 (63 %), 42-45/51 (82-88 %) and 34/35 (97 %) for Gleason 7 and 4/5 (80 %), 13/14 (93 %) and 28/28 (100 %) for Gleason ≥8 cancers respectively. At multivariate analysis, detection rates were influenced by tumour Gleason score, histological volume, histological architecture and location (P < 0.0001), but neither by field strength nor coils used for imaging. The SSS was a significant predictor of both malignancy of FAs (P < 0.005) and aggressiveness of tumours (P < 0.00001).

Conclusions: Detection rates were significantly influenced by tumour characteristics, but neither by field strength nor coils used for imaging. The SSS significantly stratified the risk of malignancy of FAs and aggressiveness of detected tumours.

Key points: • Prostate cancer volume, Gleason score, architecture and location are MRI predictors of detection. • Field strength and coils used do not influence the tumour detection rate. • Multiparametric MRI is accurate for detecting aggressive tumours. • A subjective suspicion score can stratify the risk of malignancy and tumour aggressiveness.

MeSH terms

  • Aged
  • Biopsy
  • Contrast Media / pharmacology*
  • Databases, Factual
  • Diffusion Magnetic Resonance Imaging / methods*
  • False Positive Reactions
  • Humans
  • Image Processing, Computer-Assisted / methods
  • Male
  • Middle Aged
  • Observer Variation
  • Prospective Studies
  • Prostate / pathology
  • Prostate / surgery
  • Prostate-Specific Antigen / metabolism
  • Prostatectomy / methods
  • Prostatic Neoplasms / pathology
  • Prostatic Neoplasms / surgery*
  • Reproducibility of Results

Substances

  • Contrast Media
  • Prostate-Specific Antigen