MRI for Assessing Prostate Cancer Response

Prostate cancer is one of most common cancers in America, affecting 1 in 6 men. External beam radiation therapy is one of the common methods to treat prostate cancer. Although radiotherapy is effective, side effects to the adjacent normal organs limit the therapeutic ratio. Those side effects are usually associated with the radiation damage of the normal tissue surrounding prostate, e.g. bladder, urethra and rectum etc. Both effectiveness and the side effects of radiation treatment are often accessed after whole course of radiotherapy, which makes the early intervention difficult. The current research project is a feasibility study of utilizing advanced magnetic resonance imaging (MRI) techniques to access radiotherapy treatment response of prostate cancer during and right after radiotherapy. Many advanced MRI techniques, e.g. spectroscopy (MRS), diffusion-weighted (DWI), dynamic contrast enhanced (DCE) perfusion weighted images, have been used in radiology departments for diagnostic purpose. This research project is to study the feasibility of using advanced MRI sequences to monitor tissue response during and after radiotherapy. The tissue changes revealed from MRI can provide physicians early information on possible tumor recurrence and normal tissue toxicity, therefore, the early intervention may be possible to spare normal tissue and cure the patient. The project is designed to combine several different advanced MRI imaging techniques systematically to study tissue changes during radiotherapy, which has not been seen elsewhere to date. Another important goal of this research project is to study the feasibility of associating functional MRI with radiation treatment dose distribution. Tissue response during radiation treatment depends on dose. The functional MRI can provide more information than simple anatomic information. Mapping the functional MRI spatially and associating them with 3D dose distribution in radiation treatment planning system is one important