WB Iodine Imaging Flashcards
4 types of thyroid ca
- papillary
- follicular
- medullary
- anaplastic
what 2 types of thyroid ca will iodine localizes in?
papillary + follicular
thyroid ca on scans look like… _______ masses.
solitary COLD masses
how long do is the wait after a thyroidectomy before doing a WB scan?
1-2 months
what radionuclide is used for ablation planning?
123I
why can’t we use 131I for the plan ablation dose?
it causes the cells to become stunned.
meaning it doesnt function well during the therapy dose
what is the general timeline for tx of follicular and papillary thyroid ca?
- thyroidectomy
- wait 1-2 months without hormone replacement
- ablation planning WB scan with 123I
- 131I ablation dose admin.
- 7-10 days post injection, WB scan done
- follow up imaging 6-12 months with either 123I or 131I
dose of 123I used for pre-planning + follow up scans
37-148 MBq PO
dose of 131I used for pre-planning + follow up scans
37-185 MBq PO
When do we image if using 123I?
24 hrs post admin
when do we image if using 131I?
48 hrs post admin
what type of collimators are used when using 131I?
high energy collimators
what type of collimators are used when using 123I?
medium energy, or LEHR
what window do we use when using 131I?
20-30%
what window do we use when using 123I?
15-20%
