Follow-up for Patients Exposed to I-131

Summary of Initial and Follow-up Visits for Patients Identified as Exposed to I-131 in Previous Years

Adapted from Case Studies in Environmental Medicine (CSEM): Radiation Exposure from Iodine 131, Course SS3117. (PDF - 702 KB) (HHS/ATSDR, November 2002)

Exam	Test	Results	Actions
Initial patient visit	Medical history	History of exposure only with normal examination and screening tests	Educate patient on early warning signs of thyroid and parathyroid diseases.
	Physical exam with thyroid gland palpation	Thyroid nodule found (1 cm or larger)	Begin screening workup. Schedule next visit.
	Serum thyroid stimulating hormone (TSH) level	TSH or serum free thyroxine (FT4) abnormalities	Obtain levels of serum calcium, parathyroid hormone (PTH), FT4, and antithyroid peroxidase antibodies. Refer patient to an endocrinologist, as appropriate.
		Abnormal serum calcium level	Redraw blood; if abnormal, test for PTH and refer to endocrinologist as appropriate.
		Abnormal antithyroid peroxidase antibody level	Schedule repeat exam in 1 year with palpation and thyroid function tests. Refer patient to an endocrinologist, as appropriate.
		Normal antithyroid peroxidase antibody level
Follow-up visit for a patient with a palpable thyroid nodule	Follow medical protocol for ultrasound and fine-needle aspiration biopsy	Normal or benign	Schedule next visit.
		Abnormal or nondiagnostic	Schedule for evaluation by surgeon.
During future physical examinations	Medical history update
	Serum TSH and calcium levels	Normal examination and tests	Educate patient on early warning signs of thyroid and parathyroid diseases.
		Abnormal examination or tests	Schedule for evaluation by surgeon.
	Physical exam with thyroid palpation	Thyroid nodule found (1 cm or larger)	Begin screening workup. Schedule next visit.

The frequency of examinations will depend on the presence of any thyroid abnormalities. For patients who have no abnormalities identified initially, no periodic visits are necessary but TSH should be tested when a physical is performed. For patients with abnormalities, the provider should schedule examinations at yearly intervals.

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