I had a PET Scan about 5 months after surgery and (2 months after completing the radiation & chemo) and it showed very, very minor activity on the opposite side of my neck. The doctor seemed to dismiss this activity and told us of the false positive probability, but said they would keep an eye on it. In February, through self examination, I found what I thought was a swollen node and I had some physical pain when I moved. The surgeon felt the area and told me that I had nothing to be concerned about. I went home happy, but a little part of me was still concerned. The following week, my husband and I decided to see the RO that had treated us and he said he did feel a swollen node. They ordered the CT Scan and earlier this week, Tuesday, I had the neck dissection. (Just got home from the hospital yesterday.) Not trying to be a bummer here, but I strongly feel that you have to be assertive(especially with ENT's). The good news is that the node they removed this week was only 1 cm at most.