Article Figures & Data
Tables
- TABLE 1
Representative Drugs/Supplements That Interfere With Radioiodine (in Alphabetical Order)
Name Withdrawal time Amiodarone 3–6 mo Antitussives 2–4 wk Bromides 1 wk Iodinates ointments 2–4 wk Levothyroxine (T4) 4–6 wk Lugol’s solution 2–3 wk Mineral/vitamin supplements 2–4 wk Nitrates 1 wk Perchlorate 1 wk Potassium iodide 2–3 wk Salicylates (large doses) 1 wk Steroids Variable Sulfonamides 1 wk Triiodothyronine (T3) 2–3 wk Topic Action/information needed Radioiodine-interfering materials Avoid and obtain history of (e.g., medications, intravenous contrast [especially as a part of a CT exam]) Iodine intake Compliance with low-iodine diet TSH Appropriate TSH level Stimulation Preparation with THS versus rhTSH Surgery Surgical information (e.g., total/subtotal thyroidectomy vs. lobectomy, extent of cervical compartments dissected) Histopathology Information on presence/absence of capsular or angiolymphatic invasion, extrathyroidal extension, surgical margin status, presence/extent of lymph node metastases, and level of cervical compartments involved Imaging Results of prior scintigraphy or other pertinent imaging procedures RAI treatments Information on any prior RAI treatments Physical Physical exam findings Menstruation/lactation Menstrual and lactation history, negative serum pregnancy test before RAI administration if needed Radiopharmaceuticals Administered activity (MBq [mCi]) Organ Receiving largest radiation dose (mGy/MBq [rad/mCi]) Effective dose (mSv/MBq [rem/mCi]) 18F-FDG 370–740 intravenously (10–20) 0.15 bladder wall (0.56) 0.019 (0.07) Na123I iodide (0% thyroid uptake) 74–148 by mouth (2–4) 0.097 bladder wall (0.36) 0.010 (0.039) Na131I iodide (0% thyroid uptake) 37–148 by mouth (1–4) 0.66 bladder wall (2.4) 0.058 (0.21) https://www.doseinfo-radar.com. Accessed August 18, 2020.
International Commission on Radiological Protection. Radiation Doses to Patients from Radiopharmaceuticals. New York, NY: Elsevier. 2008.
Delbeke D, Coleman RE, Guiberteau MJ, et al. Procedure guideline for tumor imaging with 18F-FDG PET/CT 1.0. J Nucl Med 2006;47:885–895.