How long do I have to wait after a nuclear medicine thyroid scan, i-123, to have a fna biopsy and/or thyroid blood tests?
Radiation... The physical half life of I-123 is approximately 13 hours. To avoid radiating the person doing the biopsy, you could wait until it clears from your system. Other than that, waiting is not necessary. .
Any time. Fna of thyroid can be done any time. Most of the time thyroid hormones are not affected by thyroid scans with i-123. However, in some occasions, depending on the iodine status and the condition of the thyroid there might be a decrease uptake of iodine by thyroid and cause transient hypothyroidism ( wolf-chiakoff phenomenon ).