Pet / ct are actually widely done in the states - Toronto not, so I think it depends on where you live. And MRI is quite definitive as well. Likely if they find no nodes they probably won't cut unless you ask them to and even then probably not. My dr. Is cautious after many years of treating this cancer. The minute he saw me he told me I'm removing the tumor and 40 nodes. Even though the ct showed no involvement. I showed him the node that had popped up before surgery the day of surgery - he said - doesn't matter it's coming out. if they do send you home and say no surgery just keep an eye on your neck for any unusual lumps, rashes etc... And go for a monthy follow up. best of luck on the scans