Functional CT imaging of prostate cancer
ABSTRACT The purpose of this paper is to investigate the distribution of blood flow (F), mean capillary transit time (Tc), capillary permeability (PS) and blood volume (vb) in prostate cancer using contrast-enhanced CT. Nine stage T2-T3 prostate cancer patients were enrolled in the study. Following bolus injection of a contrast agent, a time series of CT images of the prostate was acquired. Functional maps showing the distribution of F, Tc, PS and vb within the prostate were generated using a distributed parameter tracer kinetic model, the adiabatic approximation to the tissue homogeneity model. The precision of the maps was assessed using covariance matrix analysis. Finally, maps were compared to the findings of standard clinical investigations. Eight of the functional maps demonstrated regions of increased F, PS and vb, the locations of which were consistent with the results of standard clinical investigations. However, model parameters other than F could only be measured precisely within regions of high F. In conclusion functional CT images of cancer-containing prostate glands demonstrate regions of elevated F, PS and Vb. However, caution should be used when applying a complex tracer kinetic model to the study of prostate cancer since not all parameters can be measured precisely in all areas.
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ABSTRACT: The purpose of the study was to examine the influence of external beam radiation on the prostate and prostate cancer using novel quantitative MRI techniques. Twenty-two men, previously diagnosed with prostate cancer, were studied using T1 and T2 relaxation mapping and contrast agent kinetic methods before and after treatment by radiotherapy. The MRI findings will be correlated with biochemical (prostate specific antigen) progression and biopsy results. All 22 patients have been recruited and studied pre-treatment. So far nineteen patients have returned for follow-up MRI. The data is both complete and of a high quality. Data analysis of the pre-treatment phase has provided important and novel information about the microvascular characteristics of prostate cancer. These results have been accepted for publication in the leading radiology journal. Preliminary analysis of the post- treatment data is promising and awaits clinical interpretation.
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ABSTRACT: To use contrast material-enhanced magnetic resonance (MR) imaging and a distributed-parameter tracer kinetics model for prospectively evaluating the vascular characteristics of prostate cancer. Twenty-two patients between 57 and 76 years of age (mean age, 67 years) with histologically proved adenocarcinoma of the prostate were examined by using three-dimensional dynamic contrast-enhanced T1-weighted MR imaging at 1.5 T. The local research ethics committee approved this study, and written consent was obtained from all patients. Data from regions of interest drawn in tumor, normal-appearing peripheral zone tissue, and muscle were analyzed to provide estimates of perfusion, blood volume, interstitial volume, and microvascular permeability-surface area product. These estimates were compared by using the nonparametric Wilcoxon signed rank test. Mean blood flow was significantly (P < .001) higher in 22 prostate tumors than in 20 contralateral peripheral zones (66 vs 32 mL/100 mL/min). Similarly, the interstitial distribution volume in tumors was enlarged compared with the interstitial distribution volume in normal peripheral zones (42 vs 27 mL/100 mL). Blood volume and microvascular permeability-surface area product values in tumors (1.0 mL/100 mL and 22 mL/100 mL/min, respectively) were similar to estimated values in peripheral zone tissue (1.5 mL/100 mL and 21 mL/100 mL/min, respectively). These findings show considerable promise for isolating vascular characteristics of prostate cancer.Radiology 01/2005; 233(3):709-15. DOI:10.1148/radiol.2333032098 · 6.21 Impact Factor