| DEVELOPMENT OF FUNCTIONAL IMAGING OF THE
PROSTATE FOR THE ASSESSMENT OF BPH
Dr D L Buckley, Charles E. Hutchinson University of Manchester |
 |
Key achievements:
This is the first study of patients with BPH alone (no cancer) undertaken using quantitative dynamic contrast enhanced MRI techniques. The only similar study to date was performed in a beagle model of the condition [1]. This is also the first study in any model to assess the test-retest repeatability of a distributed parameter tracer kinetics model – that proposed by St. Lawrence and Lee [2]. Furthermore, a number of important quantitative measurements of MR relaxation have been made and tracer kinetics parameters in BPH that will provide a baseline for future studies.
Results:
Almost all aspects of the work have achieved or exceeded initial expectations. In particular, the tracer kinetic modelling has produced excellent results and will form the basis of many future studies of this technique. The measurements of T1 and T2 relaxation have proved to be both quick and reliable producing novel data. The automated measurement of prostate volume has proved challenging and this aspect of the study has not developed as far as it had been hoped. Similarly the preliminary assessment of the diffusion-weighted imaging of the prostate has highlighted the technical challenges of this type of imaging outside the head. The assessment of the histological analysis and its correlation with imaging has yet to be completed. This will take place once all the histological reports are finalised.
The next stage of research:
It is hoped to apply the techniques developed here to study two further patient groups. A characterisation of prostatitis is important as this patient group has not been studied in any depth. Prostatitis, alongside BPH, is a known confound in the diagnosis and staging of prostate cancer [3] and its characterisation may help to improve diagnostic efficacy as well as provide novel data about the condition itself. Secondly, it is hoped to examine patients who present with high PSA but negative biopsy. Quantitative MRI may help to identify those prostates with typical benign characteristics (based upon the laboratory's current findings) versus those with suspicious malignant foci (based upon the laboratory's previous studies [4,5]).
Observations:
Where is the research in the context of the whole illness? This small study is really only pilot work. The application of these techniques in the clinic requires a much larger trial to assess clinical efficacy.
How has the work done in this project advanced understanding of the subject? From the perspective of MR scientists this study has been invaluable as a pilot study to test novel quantitative techniques and their repeatability. It has also provided some of the first data characterising the vascular status of BPH in man.
How has the work done in this project brought improved treatment nearer? These data may not directly help bring treatment any nearer but it is anticipated that the techniques which have been developed will prove useful in the assessment of treatments in the future.
Personnel:
The study could not have been completed without the hard work of the following people:
Jill Youd – Research Nurse (patient recruitment)
Lucy Kershaw – PhD student (MR data analysis)
Danny Allen – Post-Doctoral scientist (image analysis)
& the Urologists at Hope Hospital.
References:
1. Jia G, Heverhagen JT, Polzer H, Jacko RV, Liang J, Zhang J, Levine AL, Rosol TJ, Knopp MV. Dynamic contrast enhanced magnetic resonance imaging as a biological marker to noninvasively assess the effect of finasteride on prostatic suburethral microcirculation. J Urol 2006;176(5):2299-2304.
2. St Lawrence KS, Lee TY. An adiabatic approximation to the tissue homogeneity model for water exchange in the brain: I. Theoretical derivation. J Cereb Blood Flow Metab 1998;18(12):1365-1377.
3. Ikonen S, Kivisaari L, Tervahartiala P, Vehmas T, Taari K, Rannikko S. Prostatic MR imaging - Accuracy in differentiating cancer from other prostatic disorders. Acta Radiol 2001;42(4):348-354.
4. Kershaw LE, Buckley DL. Precision in measurements of perfusion and microvascular permeability with T1-weighted dynamic contrast-enhanced MRI. Magn Reson Med 2006;56(5):986-992.
5. Buckley DL, Roberts C, Parker GJ, Logue JP, Hutchinson CE. Prostate Cancer: Evaluation of Vascular Characteristics with Dynamic Contrast-enhanced T1-weighted MR Imaging--Initial Experience. Radiology 2004;233(3):709-715.
Summary final report dated 02 December 2006
Project 2004/08