Iodine 131 body scanning is a nuclear study performed to assist in diagnosing metastatic thyroid cancer anywhere in the body or in detecting extrathyroidal tissue or residual thyroid tissue after a total thyroidectomy. The radionuclide 131I as MIBG I 131 is administered orally, followed by scanning to reveal concentrations in the neck, lungs, or bones, indicating metastatic activity.

• Absence of thyroid gland tissue outside of the thyroid gland; no metastatic tumor from a primary thyroid malignancy

• Inability of client to remain still during the procedure
• Other nuclear scans performed before or on the same day as the body scan

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Indications

• Determination of remaining thyroid tissue anywhere outside of the normal thyroid gland after thyroidectomy
• Determination of metastasis from a diagnosed primary thyroid malignancy
• After administration of 131I therapy for thyroid cancer

Contraindications

• Pregnancy, unless the benefits of performing the procedure greatly outweigh the risks to the fetus

[Section Outline]

• Indications
• Contraindications

Nursing Care Before the Procedure

Client teaching and physical preparation are the same as for any nuclear scan study (see section under "Brain Scanning").

• Inform the client of the scanning schedule and explain that imaging takes 2 to 3 hours.
• Ensure that changes in client's thyroid medication regimen and administration of other medications have been implemented before the study.
• History should include thyroidectomy, postoperative treatments, medication regimen, and results of other diagnostic tests and procedures.

The client is given an oral dose of the radiopharmaceutical in a capsule and returned to or requested to return to the department 24 to 72 hours later. The client is then placed on the examining table in a supine position and requested to remain still while full body scanning is performed. Thyroid-stimulating hormone (TSH) can be administered IV before the radiopharmaceutical to stimulate any residual tissue to take up the radionuclide, if this is the reason for the study. A higher level of TSH also increases uptake by metastatic tumors.

Nursing Care After the Procedure

Care and assessment after the procedure are the same as for any nuclear scan study (see section under "Brain Scanning").