Advanced Neuroimaging in Brain Tumors: Diffusion, Spectroscopy, Perfusion and Permeability for the evaluation of tumor characterization and surgical treatment planning.
The current standard of neuroimaging for brain tumor evaluation is anatomy-based MRI. Unfortunately, MRI does not fully reflect the complicated biology of infiltrative glioma, and has a limited capacity to differentiate a high-grade glioma (HGG) from a single brain metastasis. Grading of gliomas is important for the determination of appropriate treatment strategies and in the assessment of prognosis. It is clinically important to distinguish HGG from a single brain metastasis, because medical staging, surgical planning, and therapeutic decisions are different for each tumor type. The basis for this thesis was 208 patients admitted at Oslo University Hospital-Ullevål with the diagnosis of brain tumor between 2006 and 2010.
The aim of this thesis was to evaluate in terms of diagnostic examination performance in the clinical decision-making process the use of advanced MRI techniques, namely, diffusion-weighted imaging (DWI), magnetic resonance spectroscopic imaging (MRSI), and T2*-weighted first pass dynamic susceptibility contrast-enhanced perfusion MRI (DSC MRI) in the diagnosis and preoperative planning of brain tumors, with focus in the grading and characterization of gliomas, as well as in the assessment of the peri-enhancing region aiming to demonstrate tumor-infiltration and tumor-free edema.
In this thesis, we have demonstrated that MRSI and DSC MRI can be helpful to discriminate HGG from solitary metastases, supporting the hypothesis that these advanced MRI techniques can detect infiltration of tumor cells in the peri-enhancing region. We have demonstrated that combining DWI and MRSI increases the accuracy in the determination of glioma grade. We identified differences among all glial tumor grades for the parameters cerebral blood volume (rCBV) and microvascular leakage (MVL) derived from DSC MRI. Our correlation analysis indicate that MVL, rCBV, and cerebral blood flow (rCBF) may be related to different aspects of tumor angiogeneseis.
List of papers. Papers I-V are removed from the thesis due to copyright restrictions.
Paper I Server A, Kulle B, Maehlen J, Josefsen R, Schellhorn T, Kumar T, Langberg CW, Nakstad PH. Quantitative apparent diffusion coefficients in the characterization of brain tumors and associated peritumoral edema. Acta Radiol. 2009 Jul;50(6):682-9. doi:10.1080/02841850902933123
Paper II. Server A, Josefsen R, Kulle B, Maehlen J, Schellhorn T, Gadmar Ø, Kumar T, Haakonsen M, Langberg CW, Nakstad PH. Proton magnetic resonance spectroscopy in the distinction of high-grade cerebral gliomas from single metastatic brain tumors. Acta Radiol. 2010 Apr;51(3):316-25. 10.3109/02841850903482901 doi:10.3109/02841850903482901
Paper III. Server A, Kulle B, Gadmar OB, Josefsen R, Kumar T, Nakstad PH. Measurements of diagnostic examination performance using quantitative apparent diffusion coefficient and proton MR spectroscopic imaging in the preoperative evaluation of tumor grade in cerebral gliomas. Eur J Radiol. 2010 Available online 13 August 2010. doi:10.1016/j.ejrad.2010.07.017
Paper IV. Server A, Orheim TE, Graff BA, Josefsen R, Kumar T, Nakstad PH. Diagnostic examination performance by using microvascular leakage, cerebral blood volume, and blood flow derived from 3-T dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging in the differentiation of glioblastoma multiforme and brain metastasis. Neuroradiology. 2011 May;53(5):319-330 doi:10.1007/s00234-010-0740-3
Paper V. Server A, Graff BA, Orheim TE, Schellhorn T, Josefsen R, Gadmar OB, Nakstad PH. Measurements of diagnostic examination performance and correlation analysis using microvascular leakage, cerebral blood volume, and blood flow derived from 3T dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging in glial tumor grading. Neuroradiology. 2011 June;53(6):435-447 doi:10.1007/s00234-010-0770-x