6 mos after 1st round of RAI, endo is recommending another...very upset and worried

I'm looking for some guidance from those of you who have been in my shoes or know about thyroid cancer.

I had a TT in Feb. 2010 (papillary carcinoma, 1.2 cm tumor on right side) and RAI (101 millicuries) in March 2010. 10 day follow up scan showed uptake in my neck only, on the right side. They let me see the pictures and the report said I had enlarged lymph nodes on the right side.

I just had my 6 month (Thyrogen stimulated) whole body scan, and the area on the right side of my neck was completely clear. However, I saw a new spot on my left jaw / cheek area. Everything else was clear. The radiologist recommended a PET CT to hopefully rule it out as a salivary gland issue. I had the PET CT last week and the report didn't say anything about a salivary gland. It indicated that there is a small (8 mm)spot on my left side, by the suprasternal notch. This did not show up on the whole body scan (at least it wasn't mentioned in the report.) I'm no expert with this stuff, but I don't think the suprasternal notch is near my salivary gland. My Tg has been virtually undetectable since the first round of RAI (< .02) and still is at that level. Nevertheless, my endo sent me back to the radiation oncologist for a repeat round of RAI.

I met with the radiation oncologist last week and he said that 15% of his patients need 2 rounds of treatment. He felt that the right side of my neck had so much uptake that all of the other tissue didn't get treated all the way. Determining the dosage isn't a perfect science, it's probably just leftover thyroid tissue, etc. It's a small area that just didn't show up on my post RAI 10 day scan. He plans on administering another round (approx. 100 millicuries) on Nov. 29th. He said that it's no problem to do these treatments within 6 months of each other.

Ironically, right before I took the Thyrogen shots before the WBS I started having severe pain and cramping in my jaws. It started in my left side, went to the right and has happened on and off ever since. This started approx. 5.5 months after my RAI ablation. I initially had some swelling and discomfort, but it went away after a few days and it was nothing like what I'm experiencing now. When I massage my cheeks, I taste saliva / salt in my mouth. It just pours in. I asked the radiation oncologist (same one that administered my RAI in March) about this and he said it's unrelated to RAI ablation. He claims he's never had a patient experience this several months after RAI. I find this very hard to believe because even thyca.org has an article about it - http://www.thyca.org/salivary.htm.

If you're still reading this, thank you. I'm really upset about the prospect of another round of RAI. I feel like the salivary gland issue may get worse, not to mention other side effects. I'm 31 years old. My Tg looks good but there is that one spot on the PET CT (which appears to be in a different area from the whole body scan).

Any recommendations on what I should be doing now in terms of research, more testing, etc.? I'm not confident in having another round of RAI at this point. The first round was supposed to be for "peace of mind" and I was counting on only having to do it once. Should I get a second opinion and if so, from whom? (Endo, oncologist, etc.) Why would the area that lit up on my whole body scan be different from the area that lit up on my PET CT and vice versa?