Low-iodine diet revisited: importance in nuclear medicine imaging and management.
OBJECTIVE
The need for a low-iodine diet (LID) to maximize the results of radioactive iodine uptake (RAIU), nuclear medicine thyroid scintigraphy, and ultimately treatment of thyroid cancer patients is widely accepted. Failure to follow the prescribed diet can alter RAIU results, thyroid scan findings, and poststudy management.


OBJECTIVE
Provided is a case presentation that illustrates the need for adequate patient understanding and compliance with the LID.


METHODS
We present the clinical history, laboratory values, and pertinent imaging of a 21-year-old woman with papillary thyroid cancer. The patient's post-thyroidectomy I-123 and 2 subsequent thyroid (I-123 and post-RAI ablation I-131) scintigraphy examinations are reviewed as well as the patient's urine iodine levels.


RESULTS
In this case of a woman with papillary thyroid cancer, the nuclear medicine whole body and neck pinhole images revealed that compliance to an LID positively impacts the overall management. After an LID was followed, the patient's urine iodine level appropriately declined from the previously elevated level. Initial negative results on thyroid scintigraphy caused by noncompliance with the LID became positive when the patient adhered to the prescribed dietary regimen.


CONCLUSIONS
An LID is an integral element in the management of differentiated thyroid cancer. Proper guidance and emphasis on the implementation of the diet needs to be provided to patients. Noncompliance may lead to false negative imaging results, misleading the medical professionals and patient. Potentially inadequate management of the patient's thyroid cancer may follow.
Hinds
Sidney R
SR
Department of Radiology, Nuclear Medicine Service, Walter Reed Army Medical Center, 6900 Georgia Avenue N.W., Washington, DC 20307, USA. sidney.hinds@na.amedd.army.mil
Stack
Aaron L
AL
Stocker
Derek J
DJ
D000284:Administration, Oral; D000328:Adult; D016477:Artifacts; D002291:Carcinoma, Papillary / Q000000981:diagnostic imaging / Q000628:therapy; D004032:Diet; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007455:Iodine / Q000008:administration & dosage*; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D010349:Patient Compliance; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000627:therapeutic use; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000628:therapy*; D016896:Treatment Outcome
D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; D007455:Iodine