Oncology: Role of advanced MRI
Despite recent advances in surgery, radiation therapy, and chemotherapy, the prognosis for patients with brain tumours remains poor. Currently, the available treatment regimens aim at maximizing the patient's quality of life and prolonging time-to-progression and life expectancy. To accomplish these goals, the extent of safe tumour resection (EOR) on survival, in particular for patients with glioblastoma (GBM), likely extends survival. Preoperative radiological assessment that visualises the brain regions that account for critical functions (e.g. speech, hand/feet movement, visual perception) is necessary to minimise damage to healthy functionally eloquent brain tissue during the surgery.
Conventional MR imaging permits anatomical localisation of brain tumours; however, accurate assessment of relation of the tumour to eloquent cortical centres and the brain white matter tracts is limited. Functional MRI (fMRI) is a state-of-the-art method for visualising cortical brain centres and for studying their relation to brain tumours which is an essential factor in proper planning of treatment strategy. Diffusion tensor imaging (DTI) is another MRI technique that estimates the location, orientation, and integrity of the brain's white matter tracts. DTI is a useful adjunct to fMRI for mapping of the eloquent brain regions and these techniques should be part of any state-of-the-art presurgical tumour assessment for informed decision-making and surgical planning.