I just spoke to the vet. Hamilton is coming out of his box more today and head butting the assistants for petting and attention. His scans went well, and he does have thyroid nodules on both sides, but they are benign. They were lining the cats up for their radioactive iodine shots when she called, and she assured me he shouldn't experience any side effects.
Why do I feel so nervous? I miss my little one!