1Radiation Medicine Program,
Magnetization-prepared spiral imaging techniques were adapted for quantitative T2 and T1 characterization of early radiation response in patients with low/intermediate risk of localized cancer throughout 8-weeks of radiotherapy. Early central gland T2 elevation preceded persistent tumor T2 elevation, and late reduction in peripheral zone T2; observations which support a known loss of contrast in diagnostic images, and a complementary role for T2 in ADC and DCE radiation response evaluation. Zonal and tumor T1 measures were insensitive to radiotherapy. However, considerable inter-patient but minor intra-patient T1 heterogeneities support a sufficiency of baseline T1 scanning for serial quantitative perfusion analysis during radiotherapy.