MR spectroscopic imaging and diffusion‐weighted imaging of prostate cancer with Gleason scores

Abstract

Purpose: To investigate functional changes in prostate cancer patients with three pathologically proven different Gleason scores (GS) (3þ3, 3þ4, and 4þ3) using magnetic resonance spectroscopic imaging (MRSI) and diffusionweighted imaging (DWI). Materials and Methods:In this study MRSI and DWI data were acquired in 41 prostate cancer patients using a 1.5T MRI scanner with a body matrix combined with an endorectal coil. The metabolite ratios of (ChoþCr)/Cit were calculated from the peak integrals of total choline (Cho), creatine (Cr), and citrate (Cit) in MRSI. Apparent diffusion coefficient (ADC) values were derived from DWI for three groups of Gleason scores. The sensitivity and specificity of MRSI and DWI in patients were calculated using receiver operating characteristic curve (ROC) analysis. Results:The mean and standard deviation of (ChoþCr)/ Cit ratios of GS 3þ3, GS 3þ4, and GS 4þ3 were: 0.44 6 0.02, 0.56 6 0.06, and 0.88 6 0.11, respectively. For the DWI, the mean and standard deviation of ADC values in GS 3þ3, GS 3þ4, and GS 4þ3 were: 1.13 6 0.11, 0.97 6 0.10, and 0.83 6 0.08 mm 2 /sec, respectively. Statistical significances were observed between the GS and metabolite ratio as well as ADC values and GS.Conclusion: Combined MRSI and DWI helps identify the presence and the proportion of aggressive cancer (ie, Gleason grade 4) that might not be apparent on biopsy sampling. This information can guide subsequent rebiopsy management, especially for active surveillance programs.

High b Value (2,000 s/mm2) Diffusion-Weighted Magnetic Resonance Imaging in Prostate Cancer at 3 Tesla: Comparison with 1,000 s/mm2 for Tumor Conspicuity and Discrimination of Aggressiveness

“…By contrast, with ADC cut-off values of 0.92×10 −3 mm 2 /s in b values of 0, 2000 s/mm 2 , the sensitivity and specificity were 82% and 77%, respectively, suggesting that high b values were better at detecting intermediate or high risk prostate cancer when compared with standard b values. Previous studies have also reported that the ADC can discriminate between low risk cancers (Gleason score ≤6) and intermediate or high risk cancers (Gleason score ≥7) [30], [34], [35]. Therefore, in patients with prostate cancer, the ADC value may serve as a prognostic indicator.…”

MR Spectroscopy in Prostate Cancer: New Algorithms to Optimize Metabolite Quantification

“…Several papers have been published that compare receiver PAC with the more invasive ERC [16, 35,36]. Particularly, the use of ERC significantly improves spectral line width; however, good performances are obtained using PAC too.…”

“…In particular the ratios between their concentrations, i.e. (Cho+Cr)/Cit or Cho/Cit, are the variables of greatest clinical interest because of their correlation with the Gleason score [16]. Although the use of 1 H-MRS to study metabolic changes in brain and liver tumors is well established and supported by the use of recognized research software (jMRUI [17], LCMODEL [18], and Tarquin [19]), the same is not true for PCa.…”

When no treatment is the best treatment: Active surveillance strategies for low risk prostate cancers

“…Most studies using histopathology specimens as reference standards have shown that mpMRI outperforms conventional anatomical imaging alone for the detection of prostate cancer [33][34][35][36]. There is also evidence that unfavorable findings on mpMRI, especially low ADC values, are associated with adverse histological features [37,38]. Currently, almost all MRI reporting schemes are structured and use a 5-point scale to quantify the likelihood that clinically significant prostate cancer is present within a radiological region of interest.…”