Abstract #4152

Comparison Between ADC and QSI-Derived Parameters Mapping and Early Effect of Radiation Therapy in a Rodent Tumour Model

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.