Denis Rommel1, Frank Peeters1, Jorge Abarca-Quinones1, Vincent Gregoire2, Thierry Duprez1
1Medical Imaging, Universit Catholique de Louvain, Brussels, Belgium; 2Center for Molecular Imaging and Experimental Radiotherapy, Universit Catholique de Louvain, Brussels, Belgium
Q-space Imaging(QSI)-derived diffusion parameters could be more powerful in probing early micro-architectural disruption after radiation therapy (RT) than the ADC. 19 tumor xenografts in rats were examined before and three days after single-session external RT (14Gy). ADC maps at b=1000 were compared to mean value and fractional anisotropy maps for the height (RTO), width (FWHM), and kurtosis (k) of the Probability Density Function (PDF) through tensor analysis. ADC showed better sensitivity to early radiation-induced changes when compared to QSI-derived parameters. Assessment of the added value of QSI information in RT monitoring needs further investigation.