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Centre for Magnetic Resonance Investigations
Science Overview 2006/7
Achievements during 2006 – 2007
Over the previous 12 months development of prototype and conventional imaging protocols and assessment of specific receiver coils, have resulted in the CMRI becoming the UK Reference Site for GE Healthcare Ltd. for body imaging. This allows the department greater and earlier access to new software and hard ware and technical support for continuing development of state-of-the-art imaging. Advanced imaging protocols are now in place for all clinical requirements including contrast uptake assessment, image reformatting and multi-nuclear spectroscopy, providing anatomical, functional and chemical information about tissues. This translates into improved cancer patient diagnosis and optimised patient management.
The research programs include breast, prostate and gynaecological malignancy, radiotherapy planning and bone imaging related to cancer and cancer therapy. The development of surrogate MR biomarkers of tumour response to therapy continues in all areas of the portfolio and is a major theme of the CMRI.
Breast Program
Approximately 4.5% of breast cancer patients undergo neoadjuvant chemotherapy (NAC) for locally advanced cancer to increase the likelihood of conserving surgery and improve outcome by reducing incidence of systemic micro-metastases. However, a number of these patients do not respond to NAC and usually less than 30% obtain a complete or optimal response. In the poor responders the ineffective therapy has decreased quality of life, increased costs, and may adversely effect disease free survival by delaying initiation of effective treatment. The accurate and early prediction of response to NAC would allow individualisation of treatment and improve outcome.
Currently it is not possible to identify patients who are more likely to respond to a particular chemotherapy, or to determine which type of chemotherapy would be most effective. Tumour destruction, as measured by tumour shrinkage, typically only becomes apparent towards the end of treatment, but in some breast cancers chemotherapy has been found to induce MR detectable changes within 24 hrs of treatment. Initial research from the CMRI, using multi-parametric quantitative MRI incorporating pharmacokinetic modelling of contrast-enhanced data, T2 and ADC mapping, and spectroscopy, has demonstrated that the overall effectiveness of a specific NAC regime can be determined at an early stage using advanced functional magnetic resonance (MR) imaging. Verification of these findings in a larger patient group, using varied NAC regimes, is being developed to determine the optimal investigation protocol and generalisability to all NAC regimes. Manual MR tumour size estimation is highly accurate but labour intensive. Consequently semi-automated techniques for data analysis which also allow detailed quality analysis and which are appropriate for a multi-centre study are being developed.
Gynaecology Program
This program incorporates studies to optimise the differentiation of benign from malignant pelvic masses, accurately stage disease to determine operability essential to optimise initial management; predict response to treatment in both the neoadjuvant and adjuvant settings; and detect tumour recurrence using conventional imaging and MR spectroscopy. Initial review of data from the first 161 patients with primary ovarian cystic lesions revealed a sensitivity of 92% and specificity of 84% (5 FIGO stage 1A borderline tumours not detected). The staging accuracy demonstrated very good agreement between MRI and histopathology, indeed the results were not significantly different from subsequent laparotomy, obviating the need for staging surgery.
The ability of MR to predict response for locally advanced cancer of the cervix to chemo-radiotherapy is being investigated early during treatment using contrast-uptake data, R2 and ADC mapping, and single voxel proton spectroscopy. This is compared with in vitro examination of tumour biopsies using nuclear magnetic resonance spectroscopy operating at 8T.
Prostate Program
The diagnostic accuracy data at 3T for extra-capsular prostate tumour extension (47 radical prostatectomy specimens) has been evaluated using quantification of MR derived functional information, including blood flow, the apparent diffusion coefficient of water, and the chemical composition of prostate tissue. Parallel imaging available at 3T, allows increased temporal resolution allowing measurement of an arterial input function. This provides 3D information on a pixel-by-pixel basis of maps of lesion extent potentially useful for tumour volume determination. The diagnostic potential of these parameters is being compared with radical prostatectomy specimens and has achieved a diagnostic accuracy of 92% (sensitivity 70%; specificity 97%). The role of an additional endo-rectal coil for prostate imaging shows promise in further increasing diagnostic accuracy. Techniques developed for cancer staging are being implemented for investigations of patients with an elevated prostate specific antigen level, but with negative biopsy findings, together with patients with prostate intra-epithelial neoplasia (in situ malignancy) in whom the detection of small volume invasive disease will aid early treatment.
Other studies
The efficacy of incorporating functional and anatomical MR data into radiotherapy treatment planning of head / neck tumours is under investigation. Software has been produced to incorporate morphologically optimised enhancement data which is more suitable for contouring and planning radiotherapy distributions.
Work is on going to fuse dynamic contrast enhanced (DCE) imaging in a DICOM compliant format with CT derived information, for input into the radiotherapy planning system. Such conformal plans would improve tumour control and reduce side effects by boosting dose to the vascular part of the planning target volume. In parallel gel dosimetry (in collaboration with York University) is being further developed, for multi-centre use, to verify by MR imaging these complex dose distributions.
MR spectroscopy and innovative imaging sequences, which provide water and fat only images, are being employed to investigate normal bone marrow composition. These techniques together with the evaluation of trabecular structure, using segmentation and quantification of high resolution MR images, are being developed to follow late osteoporotic effects in cancer patients following treatment.
Link to
YCR science overview 2002/3
YCR science overview 2003/4
YCR science overview 2004/5
YCR science overview 2005/6
Programme of research 2001/2
Programme of research 2002/3
Programme of research 2003/4
Programme of research 2004/5
Programme of research 2005/6
Programme of research 2006/7
Publications 2001/2
Publications 2002/3 - no list of publications available
Publications 2003/4
Publications 2004/5
Publications 2005/6
Publications 2006/7
Reports 2001/2
Reports 2002/3
Reports 2003/4
Reports 2004/5
Reports 2005/6
Reports 2006/7
Hull University Centre for Magnetic Resonance Investigations site: www.hull.ac.uk/mri
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