Aberdeen Biomedical Imaging Centre
Research Area: Cancer Imaging
Research is carried out in the following areas:CADET II: A multicentre randomised evaluation of computer aided detection (CAD) in the UK NHS Breast Screening Programme
In the NHS Breast Screening Programme over 1.5 million breast X-rays (mammograms) are read by specialist radiologists or breast clinicians each year. Computer aided detection (CAD) systems have been developed as a method of attracting attention to suspicious features that may be overlooked by the reader. There is also some evidence that CAD systems are capable of 'prompting' cancers at an earlier stage than would be detected by a human reader.
Professor Gilbert and collaborators in Aberdeen, Manchester and London recently completed a preliminary retrospective study (CADET) funded by Cancer Research UK in which a random sample of over 10,000 mammograms from 1996 were re-read using CAD. The results of the CADET study indicated that the performance of a single reader using CAD matched that of the previous double reading in detecting breast cancer cases. CADET II is an extension of this comparison into the real life setting of the screening programme. If the results of this prospective study confirm the observations of the CADET study, CAD could provide a solution to the manpower problems in the breast screening service.
The study involves Professor Gilbert and Dr Maureen Gillan in Aberdeen and collaborators in the breast screening centres in Manchester, Coventry and Nottingham, and Professor Stephen Duffy of Cancer Research UK in London.
COGNATE (Cancer of the Oesophagus or Gastricus: New Assessment of the Technology of Endosonography)
Endoscopic ultrasound (EUS) has been recommended as an essential staging investigation for patients with gastric or oesophageal cancer on the basis that it has the potential to improve the selection of patients for surgery or alternative multi-modality treatments. However, there are few reports of robust evidence based criteria to support its widespread use and, in particular, no large scale comparisons of EUS and modern helical CT scans.
The COGNATE trial is a pragmatic multi-centre randomised trial comparing the outcome of patients with gastric and oesophageal cancers who are staged with or without EUS. The trial will provide a clinical, social and economic evaluation of EUS to underpin the development of guidelines as to the most effective staging of patients with gastric and oesophageal cancers and for which patient groups EUS staging is likely to be beneficial in terms of patient outcome.
The trial is coordinated from the University of Wales Bangor and involves hospitals in Aberdeen, Dundee, Glasgow, Leicester, Gloucester, Blackburn and Tyne and Wear.
MR in Cancer
Two broad research interests.
- Development of functional imaging as a monitoring tool for early indication of cancer response to therapy.
- Development of functional imaging biomarkers as indicators of cancer response potential pre-therapy.
Both of these themes have been explored using data from patients with large or locally advanced breast cancer receiving neoadjuvant chemotherapy (1-5). This work has focussed on the development of MR biomarkers of response using a series of multi-compartment models that can be used to categorise tumour vascular kinetics according to pharmacokinetic parameters describing flow, permeability and vascular density. We have also developed a novel delivery relationship between the vascular and metabolic aspects of tumour physiology using a combination of MR and PET imaging in breast cancer, with MR biomarkers identified pre-therapy predicting reduction in tumour metabolism after administration of chemotherapy (1,3,5).
This work has been expanded to include patients with locally advanced rectal, cervical, and ovarian cancers receiving chemotherapy, chemoradiotherapy, anti-angiogenic and radiotherapy treatments (data currently being acquired and analysed). These studies also include diffusion-weighted MR which allows calculation of the Apparent Diffusion Coefficient (ADC) of tissue, a parameter which is influenced by the amount of water diffusion in tissue and therefore sensitive to cell apoptosis. Previous work in rectal cancers has demonstrated that pre-therapy ADC may be indicative of eventual tumour response to therapy, and early changes in ADC values have also been shown to indicate a positive response to therapy.
- Semple SIK, Gilbert FJ, Redpath TW, Ahearn TS, Welch AE. Correlation of MRI-PET rim enhancement in breast cancer. A delivery related phenomenon with therapy implications? Lancet Oncology 4(12): 759, 2003.
- Ahearn TS, Staff RT, Redpath TW, Semple SIK. The effects of renal variation upon measurements of perfusion and leakage volume in breast tumours. Physics in Medicine and Biology 49(10): 2041-2051, 2004.
- Semple SIK, Gilbert FJ, Redpath TW, Staff RT, Ahearn TS, Welch AE, Heys SD, Hutcheon AW, Smyth EH, Chaturvedi S. The relationship between vascular and metabolic characteristics of primary breast tumours. European Radiology 14(11): 2038-2045, 2004.
- Ahearn TS, Staff RT, Redpath TW, Semple SIK. The use of the Levenberg-Marquardt curve-fitting algorithm in pharamcokinetic modelling of DCE-MRI data. Physics in Medicine and Biology 50(9): N85-N92, 2005.
- Semple SIK, Staff RT, Gilbert FJ, Heys SD, Redpath TW, Welch AE, Sharp PF, Ahearn TS, Hutcheon AW, Smyth EH, Chaturvedi S. Baseline delivery characteristics predict change in invasive ductal breast carcinoma metabolism as a result of primary chemotherapy administration. Annals of Oncology 2006 (in press).
Breast Imaging
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