Department of Urology, Institut Jules Bordet, Brussels, Belgium.
Magnetic resonance imaging (MRI) and MR spectroscopic imaging (MRSI) have been gaining acceptance as tools in the evaluation of prostate cancer. We compared the accuracy of transrectal ultrasound (TRUS)-guided biopsy and dynamic contrast-enhanced MRI combined with three-dimensional (3D) MRSI in locating prostate tumours and determined the influence of prostate weight on MRI accuracy.
Between March 1999 and October 2006, 507 patients with localised prostate cancer underwent radical prostatectomy (RP) at the Jules Bordet Institute. Of these, 220 had undergone endorectal MRI (1.5 T Siemens Quantum Symphony) and 3D-MRSI prior to RP. We retrospectively reviewed data on tumour location and compared the results obtained by MRI and by TRUS-guided biopsy with those obtained on histopathology of the RP specimen.
Patient data were as follows: median age 62.4 years (45-74); median PSA 6.36 ng/ml (0.5-22.6); 73.6% of patients had non-palpable disease (T1c); median biopsy Gleason score 6 (3-9); median RP specimen weight 50 g (12-172); median pathological Gleason score 7 (4-10); 68.64% of patients had organ-confined (pT2) disease. Tumour localisation was correlated with RP data in a significantly higher percentage of patients when using MRI rather than TRUS-guided biopsy (47.4 vs. 36.6%, p < 0.0001). MRI was marginally superior to TRUS-guided biopsy in detecting malignancy at the prostate apex (48.3 vs. 41.9%, p = 0.0687) and somewhat better at the prostate base (46 vs. 39.1%, p = 0.0413). It was highly significantly better at mid-gland (52 vs. 41.1%, p = 0.0015) and in the transition zone (40.1 vs. 24.3%, p < 0.0001). MRI had higher sensitivity in larger (≥50 g) than smaller (< 50 g) prostates (50.3 vs. 42.2%, p = 0.0017).
MRI was superior to TRUS-guided biopsy in locating prostate tumours except at the gland apex. MRI was more accurate in larger (≥50 g) than smaller prostates.
Goris Gbenou MC, Peltier A, Addla SK, Lemort M, Bollens R, Larsimont D, Roumeguère T, Schulman CC, van Velthoven R. Are you the author?
Reference: Urol Int. 2011 Oct 15. Epub ahead of print.