Kallehauge, Jesper Folsted10; Tanderup, Kari10; Duan, Chong8; Haack, Soren10; Pedersen, Erik Morre11; Lindegaard, Jacob Christian10; Fokdal, Lars Ulrik10; Mohamed, Sandy Mohamed Ismail10; Nielsen, Thomas12
1 Department of Clinical Medicine - The Department of Oncology, Department of Clinical Medicine, Health, Aarhus University2 Department of Clinical Medicine - Department of Medical Physics, Department of Clinical Medicine, Health, Aarhus University3 Department of Clinical Medicine - MTA, Department of Clinical Medicine, Health, Aarhus University4 Department of Clinical Medicine, Health, Aarhus University5 Diagnostic Radiology, Department of Clinical Medicine, Health, Aarhus University6 Interdisciplinary Nanoscience Center - INANO-Kemi, iNANO-huset, Interdisciplinary Nanoscience Center, Science and Technology, Aarhus University7 Department of Clinical Medicine - Department of Experimental Clinical Oncology, Department of Clinical Medicine, Health, Aarhus University8 Department of Chemistry, Bagley Hall, University of Washington9 Aarhus University School of Engineering - Electronics, Aarhus University School of Engineering, Science and Technology, Aarhus University10 Department of Clinical Medicine - The Department of Oncology, Department of Clinical Medicine, Health, Aarhus University11 Department of Clinical Medicine, Health, Aarhus University12 Aarhus University School of Engineering - Electronics, Aarhus University School of Engineering, Science and Technology, Aarhus University
Background. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) offers a unique capability to probe tumour microvasculature. Different analysis of the acquired data will possibly lead to different conclusions. Therefore, the objective of this study was to investigate under which conditions the Tofts (TM), extended Tofts (ETM), compartmental tissue uptake model (C-TU) and 2-compartment exchange model (2CXM) were the optimal tracer kinetic models (TKMs) for the analysis of DCE-MRI in patients with cervical cancer. Material and methods. Ten patients with locally advanced cervical cancer (FIGO: IIA/IIB/IIIB/IVA-1/5/3/1) underwent DCE-MRI prior to radiotherapy. From the two-parameter TM it was possible to extract the forward volume transfer constant (Ktrans) and the extracellular-extravascular volume fraction (ve). From the three-parameter ETM, additionally the plasma volume fraction (vp) could be extracted. From the three-parameter C-TU it was possible to extract information about the blood flow (Fp), permeability-surface area product (PS) and vp. Finally, the four-parameter 2CXM extended the C-TU to include ve. For each voxel, corrected Akaike information criterion (AICc) values were calculated, taking into account both the goodness-of-fit and the number of model parameters. The optimal model was defined as the model with the lowest AICc. Results. All four TKMs were the optimal model in different contiguous regions of the cervical tumours. For the 24 999 analysed voxels, the TM was optimal in 17.0%, the ETM was optimal in 2.2%, the C-TU in 23.4% and the 2CXM was optimal in 57.3%. Throughout the tumour, a high correlation was found between Ktrans(TM) and Fp(2CXM), ρ = 0.91. Conclusion. The 2CXM was most often optimal in describing the contrast agent enhancement of pre-treatment cervical cancers, although this model broke down in a subset of the tumour voxels where overfitting resulted in non-physiological parameter estimates. Due to the possible overfitting of the 2CXM, the C-TU was found more robust and when 2CXM was excluded from comparison the C-TU was the preferred model.
Acta Oncologica, 2014, Vol 53, Issue 8, p. 1064-1072