The Hypothalamic-Pituitary-Thyroid Axis in Infants and Children: Protection from Radioiodines

Table 5

Inhibition of radioactive iodide uptake (RAIU) into the thyroid gland by potassium or sodium iodide in children and adults.

Subject, KI dose (mg)	RAIU (% thyroidal radiotracer dose)	RAIU inhibition (% of radiotracer dose)	Reference; location
Adult	30 hr RAIU	RAIU % inhibition	[30]; England
247 (𝑛=1)	38	100 at 30 hr, 16 at 5 days
124 (𝑛=1)	45	96 at 30 hr, 22 at 5 days
37 (𝑛=1)	44	86 at 30 hr, 16 at 3 days
25 (𝑛=1)	39	97 at 30 hr
5 (𝑛=1)	52	54 at 30 hr
Adult	24 hr RAIU	24 hr RAIU % inhibition	[16]; United States
10 (𝑛=5)	19.4	36
30 (𝑛=15)	19.4 to 22.6	93 to 96
50 (𝑛=5)	19.7	92
100 (𝑛=5)	17.2	96
Adult, NaI	24 hr RAIU	24 hr RAIU inhibition	[31]; United States
5 (𝑛=1)	33	78
25 (𝑛=1)	41	96
50 (𝑛=1)	28	97
100 (𝑛=13)	28.6	97.8
200 (𝑛=10)	25.9	98.5
1000 (𝑛=1)	19	99.0
Adult (hyperthyroidism)	24 hr RAIU	24 hr RAIU inhibition	[32]; Japan
50 (𝑛=8 for both doses); 100	65.3 for 8 patients	73.3; 79.5
Children	1-2 day RAIU	24 hr RAIU inhibition	[15]; United States
1.8 (𝑛=2, 8, and 9 years of age)	21 and 25	33 and 48
Children (𝑛=5, 2 years of age)	24 hr RAIU	24 hr RAIU % inhibition	[12]; United States
0.3	≈15 to 25	≈20 to 55
0.6	≈15 to 25	≈47 to 67