Prospective Assessment of Prostate Cancer Aggressiveness Using 3-T Diffusion-Weighted Magnetic Resonance Imaging-Guided Biopsies Versus a Systematic 10-Core Transrectal Ultrasound Prostate Biopsy Cohort

Department of Radiology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
European Urology (Impact Factor: 13.94). 08/2011; 61(1):177-84. DOI: 10.1016/j.eururo.2011.08.042
Source: PubMed


Accurate pretreatment assessment of prostate cancer (PCa) aggressiveness is important in decision making. Gleason grade is a critical predictor of the aggressiveness of PCa. Transrectal ultrasound-guided biopsies (TRUSBxs) show substantial undergrading of Gleason grades found after radical prostatectomy (RP). Diffusion-weighted magnetic resonance imaging (MRI) has been shown to be a biomarker of tumour aggressiveness.
To improve pretreatment assessment of PCa aggressiveness, this study prospectively evaluated MRI-guided prostate biopsies (MR-GBs) of abnormalities determined on diffusion-weighted imaging (DWI) apparent diffusion coefficient (ADC) maps. The results were compared with a 10-core TRUSBx cohort. RP findings served as the gold standard.
A 10-core TRUSBx (n=64) or MR-GB (n=34) was used for PCa diagnosis before RP in 98 patients.
Using multiparametric 3-T MRI: T2-weighted, dynamic contrast-enhanced imaging, and DWI were performed to identify tumour-suspicious regions in patients with a negative TRUSBx. The regions with the highest restriction on ADC maps within the suspicions regions were used to direct MR-GB. A 10-core TRUSBx was used in a matched cohort. Following RP, the highest Gleason grades (HGGs) in biopsies and RP specimens were identified. Biopsy and RP Gleason grade results were evaluated using chi-square analysis.
No significant differences on RP were observed for proportions of patients having a HGG of 3 (35% vs 28%; p=0.50), 4 (32% vs 41%; p=0.51), and 5 (32% vs 31%; p=0.61) for the MR-GB and TRUSBx cohort, respectively. MR-GB showed an exact performance with RP for overall HGG: 88% (30 of 34); for TRUS-GB it was 55% (35 of 64; p=0.001). In the MR-GB cohort, an exact performance with HGG 3 was 100% (12 of 12); for HGG 4, 91% (10 of 11); and for HGG 5, 73% (8 of 11). The corresponding performance rates for TRUSBx were 94% (17 of 18; p=0.41), 46% (12 of 26; p=0.02), and 30% (6 of 20; p=0.01), respectively.
This study shows prospectively that DWI-directed MR-GBs significantly improve pretreatment risk stratification by obtaining biopsies that are representative of true Gleason grade.

Download full-text


Available from: Stefan A W Bouwense, May 31, 2014
  • Source
    • "Recent studies have shown that both DWI and spectroscopic imaging are correlated with the Gleason grade. Low ADC values—as confirmed by our pathologic-radiologic correlation—and high choline-to-creatine ratio are associated with an increasing Gleason score [16] [17] [18]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: To assess whether the proportion of men with clinically significant prostate cancer (PCa) is higher among men randomized to multiparametric magnetic resonance imaging (mp-MRI)/biopsy vs. those randomized to transrectal ultrasound (TRUS)-guided biopsy.Methods In total, 1,140 patients with symptoms highly suggestive of PCa were enrolled and divided in 2 groups of 570 patients to follow 2 different diagnostic algorithms. Group A underwent a TRUS-guided random biopsy. Group B underwent an mp-MRI and a TRUS-guided targeted+random biopsy. The accuracy of mp-MRI in the diagnosis of PCa was calculated using prostatectomy as the standard of reference.ResultsIn group A, PCa was detected in 215 patients. The remaining 355 patients underwent an mp-MRI: the findings were positive in 208 and unremarkable in 147 patients. After the second random+targeted biopsy, PCa was detected in 186 of the 208 patients. In group B, 440 patients had positive findings on mp-MRI, and PCa was detected in 417 at first biopsy; 130 group B patients had unremarkable findings on both mp-MRI and biopsy. In the 130 group B patients with unremarkable findings on mp-MRI and biopsy, a PCa Gleason score of 6 or precancerous lesions were detected after saturation biopsy. mp-MRI showed an accuracy of 97% for the diagnosis of PCa.Conclusions The proportion of men with clinically significant PCa is higher among those randomized to mp-MRI/biopsy vs. those randomized to TRUS-guided biopsy; moreover, mp-MRI is a very reliable tool to identify patients to schedule in active surveillance.
    Full-text · Article · Nov 2014 · Urologic Oncology
  • Source
    • "ADC values and their corresponding Gleason scores [19]. In another study by Hambrock et al., prostate lesions with the highest restriction determined on ADC maps were associated with higher grade tumors [21]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Multiparametric magnetic resonance imaging (MP-MRI) has emerged as a promising method for the detection of prostate cancer. The functional MRI components of the MP-MRI consist of the diffusion weighted MRI, dynamic contrast enhanced MRI, and magnetic resonance spectroscopic imaging. The purpose of this paper is to review the existing literature about the use of functional MRI in prostate cancer detection.
    Full-text · Article · Jul 2014 · BioMed Research International
  • Source
    • "The independent transition probabilities [12] [13] [21] [22] and diagnostic accuracy data used for the TRUSGB strategy were derived from systematic review of the literature [12,23–26] (Table 1). The accuracy data from the mp-MRI are based on the values estimated through a meta-analysis [27]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: The current diagnostic strategy using transrectal ultrasound-guided biopsy (TRUSGB) raises concerns regarding overdiagnosis and overtreatment of prostate cancer (PCa). Interest in integrating multiparametric magnetic resonance imaging (MRI) and magnetic resonance-guided biopsy (MRGB) into the diagnostic pathway to reduce overdiagnosis and improve grading is gaining ground, but it remains uncertain whether this image-based strategy is cost-effective. To determine the cost-effectiveness of multiparametric MRI and MRGB compared with TRUSGB. A combined decision tree and Markov model for men with elevated prostate-specific antigen (>4 ng/ml) was developed. Input data were derived from systematic literature searches, meta-analyses, and expert opinion. Quality-adjusted life years (QALYs) and health care costs of both strategies were modelled over 10 yr after initial suspicion of PCa. Probabilistic and threshold analyses were performed to assess uncertainty. Despite uncertainty around the presented cost-effectiveness estimates, our results suggest that the MRI strategy is cost-effective compared with the standard of care. Expected costs per patient were €2423 for the MRI strategy and €2392 for the TRUSGB strategy. Corresponding QALYs were higher for the MRI strategy (7.00 versus 6.90), resulting in an incremental cost-effectiveness ratio of €323 per QALY. Threshold analysis revealed that MRI is cost-effective when sensitivity of MRGB is ≥20%. The probability that the MRI strategy is cost-effective is around 80% at willingness to pay thresholds higher than €2000 per QALY. Total costs of the MRI strategy are almost equal with the standard of care, while reduction of overdiagnosis and overtreatment with the MRI strategy leads to an improvement in quality of life. We compared costs and quality of life (QoL) of the standard "blind" diagnostic technique with an image-based technique for men with suspicion of prostate cancer. Our results suggest that costs were comparable, with higher QoL for the image-based technique.
    Full-text · Article · Dec 2013 · European Urology
Show more