Spatially matched in vivo and ex vivo MR metabolic profiles of prostate cancer – investigation of a correlation with Gleason score. (27th December 2012)

• Record Type: Journal Article
• Authors: Selnæs, Kirsten M.; Gribbestad, Ingrid S.; Bertilsson, Helena; Wright, Alan; Angelsen, Anders; Heerschap, Arend; Tessem, May‐Britt
• Is Part Of: NMR in biomedicine. Volume 26:Number 5(2013:May)
• Page Start: 600
• Page End: 606
• Publication Date: 2012-12-27
• Subjects: MRS and MRSI -- high‐resolution magic angle spinning -- metabolite ratios -- prostate cancer aggressiveness -- HR MAS MRS; Nuclear magnetic resonance -- Periodicals; Magnetic Resonance Spectroscopy -- Periodicals; 574
• DOI: 10.1002/nbm.2901
• Languages: English
• ISSNs: 0952-3480

Abstract

Abstract : MR metabolic profiling of the prostate is promising as an additional diagnostic approach to separate indolent from aggressive prostate cancer. The objective of this study was to assess the relationship between the Gleason score and the metabolic biomarker (choline + creatine + spermine)/citrate (CCS/C) measured by ex vivo high‐resolution magic angle spinning MRS (HR‐MAS MRS) and in vivo MRSI, and to evaluate the correlation between in vivo ‐ and ex vivo ‐measured metabolite ratios from spatially matched prostate regions. Patients ( n = 13) underwent in vivo MRSI prior to radical prostatectomy. A prostate tissue slice was snap‐frozen shortly after surgery and the locations of tissue samples ( n = 40) collected for ex vivo HR‐MAS were matched to in vivo MRSI voxels ( n = 40). In vivo MRSI was performed on a 3T clinical MR system and ex vivo HR‐MAS on a 14.1T magnet. Relative metabolite concentrations were calculated by LCModel fitting of in vivo spectra and by peak integration of ex vivo spectra. Spearman's rank correlations ( ρ ) between CCS/C from in vivo and ex vivo MR spectra, and with their corresponding Gleason score, were calculated. There was a strong positive correlation between the Gleason score and CCS/C measured both in vivo and ex vivo ( ρ = 0.77 and ρ = 0.69, respectively; p < 0.001), and between in vivo and ex vivo metabolite ratios from spatially matched regions ( ρ = 0.67, p < 0.001). Our data indicate that MR metabolic profiling is a potentially useful tool for the assessment of cancer aggressiveness. Moreover, the good correlation between in vivo ‐ and ex vivo ‐measured CCS/C demonstrates that our method is able to bridge MRSI and HR‐MAS molecular analysis. Copyright © 2012 John Wiley & Sons, Ltd. Abstract : A significant correlation was found between the metabolite ratio (choline + creatine + spermine)/citrate (CCS/C) in prostate cancer and the Gleason score when measured by in vivo MRSI and ex vivo high‐resolution magic angle spinning of tissue samples. Stratification of the cancers into low‐ and high‐risk groups of aggressiveness revealed a significant difference in CCS/C between these clinically relevant patient groups both in vivo and ex vivo . Finally, a strong correlation was observed between the in vivo ‐ and ex vivo ‐measured metabolite ratios from spatially matched regions.