The only place I know of in Oregon is OHSU Knight Cancer Institute in Portland. They would probably be able to give you that mpMRI I mentioned. They might have
locations around the state as well. Perhaps call them
to arrange a consultation.
Image guided radiation therapy (IGRT) is needed when there is a squirrely prostate in place, but less necessary when the prostate is gone - they just use the pelvic bones as their visual reference. But if they want to use the mpMRI to zoom in on a specific place, they might want to add image guidance for extra precision. It usually involves implanting gold fiducial markers (the size of rice grains). They normally do it into the prostate, but sometimes for salvage they do it into the prostate bed instead. All of these are details your RO can better explain.