I hope the PRRT has been working well for your wife. I'm part of a study at Mayo and recieved CT scans throughout the study. The treatment phase is complete and I will continue to have CT scans as follow up every few months. I did have the gallium PET scan prior to treatment choices. I'm sure your oncologist will explain the rationale for his choices. It's good that you ask questions and get answers. The anxiety of wondering and worries isn't good for her health and healing. My best wishes for you both.