The scans I have had so far during surveillance and only CT scans. My oncologist says that if anything on these scans changes significantly he will probably have me do a PET scan to further define things. He is very expert and experienced in this field and I trust his advice. However, I do wonder if a PET scan might be generally more useful than a CT scan. He feels CT scans are adequate to detect tumor return or metastasis. I believe insurance coverage is also an issue. For insurance to cover, I think you have to have a CT scan and indications that a PET scan is needed before it is covered because it is a more expensive test. I've been told that there is no way in my case of a diffuse area in the pancreatic bed to completely tell what might be cancer and what might be scar tissue.