Changes in Dynamic Contrast Enhanced MRI Paramters in the First 8 Weeks of Prostate Radiotherapy

Masoom A. Haider¹, Peter Chung², Warren Foltz², Anna Kirilova², Charles Catton², Padraig Warde², Andrew Bayley², Robert Bristow², Michael Milosevic², Cynthia Menard²

Twelve patients underwent DCE MRI of the prostate prior and at 2, 4, 6, and 8 weeks during external bean radiotherapy. There was a significant moderate positive correlation between cumulative radiation dose and percent change in Ktrans, ve, and IAUCC60 for the whole prostate, peripheral zone and transition zone (0.53-0.69, p<0.0005). The overall pattern consisted of a maximal two week incremental increase occurring in the first 4 weeks during therapy. The 2-4 week period during the course of radiotherapy may be the best time to assess the potential prognostic value of DCE MRI.