I have struggled with this decision as well. I had a TT on 5/21/08 due to 2.2cm papillary tumor, and am scheduled to have a 100 mCi RAI treatment in July for remnant ablation. While the evidence suggests a potential false negative rate of 20%+ for the diagnostic use of Thyrogen-assisted RAI, it appears that a lot of doctors and many patients feel the benefits (not going hypo) outweigh the drawbacks (potential false negative). However, in my mind, the post-surgery remnant ablation procedure is a totally different animal altogether. I do not want to take a 20%+ chance that the remnant ablation does not work. If there was a chance that the procedure would not work because of the use of Thyrogen, I would go through "hypo-hell" to get the job done. Crikey, it just got approved by the FDA for remnant ablation 6 months ago.
On the othe hand, everything I can find on the web suggests that with regard to therapeutic doses, Thyrogen-assisted RAI is just as, if not more, effective as hormone withdrawal. Also, it has been approved for use in this indication in Europe since 2005. I have also heard that major cancer centers such as M.D. Anderson and Sloan Kettering are using Thyrogen for remnant ablation almost exclusively (this is second-hand and I can not verify this).
At the end of the day, I think I have decided to use the Thyrogen. I guess there is a risk with every decision, but for me, there is enough positive evidence out there to support the use of it. Keep us informed about your decision!
Tim