I believe the uptake scan is outdated and unnecessary but it was a matter of course in the 1990s. Are you seeing an endocrinologist who specializes in thyroid issues?
As squeegee said, you don't need a total thyroidectomy, but if you have multiple cysts (as my friend did) they generally remove the whole thing or you will just end up having more trouble down the road. Also, if they have any suspicion it's cancer, they like to remove the whole thing.
I had all my stuff done in 1994. Thyroid cancer was much more rare then and no internet to learn anything. Mine had a very rare chance of being cancerous, so I only had a lobectomy. Even on the operating table, the biopsy came back benign. After the full pathology was done; however, I got the cancer diagnosis. I then had to go back in for surgery 2 weeks later to get the rest of the gland removed. I had no more cysts in there (although maybe the early signs of one) but the remaining half also had small sprinkles of cancerous cells in it. So had I not had the whole thing out, this would have gotten me later.
Thyroid biopsies, unfortunately, are funny things. If a get a biopsy that is positive for cancer cells, you can consider that to be a good biopsy. If the biopsy comes back clear, it's actually not 100% guaranteed that you are clear. Kind of stinks, but that that's how it is.