I was diagnosed with SCC of the right tonsil last November and underwent all my prescribed treatments. When I was first diagnosed I received a PET scan that showed no active cancer. A CT scan revealed that it had actually spread to 4 lymph nodes in my neck. I've had 2 additonal PETs since then and neither of them "lit up". As I talk to more and more cancer survivors and read posts on cancer boards like this one I am struck by how many people have had clean PET scans when they indeed did have cancer. Is this test unreliable? Has anybody else noticed this? As I think now I can't recall hearing from anybody that they've had a PET scan come out positive even though they were diagnosed with cancer. I don't think I have much confidence in PETs as a diagnostic tool.