I had a CAT scan (first one) three weeks ago. The radiologist opinion was that all was clean. My physican had a concern on a lymph node in my right side which is the side of the original cancer, stage 1, floor of mouth, surgery to remove in May 04, clean margins though the sential node was not found, a fairly wide sweep of the nodes in the right side of the neck showed no cancer. The node noticed on the CAT scan was 50% larger than the corresponding node on the left side so he ordered a PETscan (first one). Thankfully, the results came back negative. However, I am concerned on the reliability of the PETScan, possibility of false negatives was mentioned by my physican. I spoke to the nurses giving the PETscan and their opinion was that PETscans have a very high rate of dependability. I will see my physican tomorrow to discuss further. I believe he is going to recommed full right neck dissection regardless of PETscan findings and dependent on that result, radiation if nodes are positive. Any conmments on PETscan experience and reliability would be appreciated.