I like your idea to go over PET and CT scan reports with your GP. I do the same thing with my PCP. I have found that Specialists don't discuss other things noted in a scan report if outside their area of specialization. So, I have my PCP review reports and ask him if he thinks there is anything I need to follow up on. I am in fact now following up with something that was noted on a scan. I do find the Radiologist reports will suggest when another type test would be needed to determine something.
I had to go to ER last year and they discovered I had pleurisy. I saw my PCP immediately after and he went over the ER reports and then ordered two inflammatory marker tests (CRP and ESR) which the ER had not done. They came back very elevated! That was an important piece of information. The pleurisy decreased and the inflammatory markers went down to normal. When you have multiple conditions, it helps to work closely with your PCP, to keep things from falling through the cracks.