Increasing the Radioiodine Dose Does Not Improve Cure Rates in Severe Graves' Hyperthyroidism: A Clinical Trial with Historical Control

Table 1

Baseline characteristics of patients with Graves’ hyperthyroidism and a thyroid volume ≥48 mL, according to study group.

	Group200 μCi/mL/RAIU (𝑛=15)	Group 250 μCi/mL/RAIU (𝑛=15)	𝑃
Sex (F/M)	12/3	11/4	1.000
Age (years)	34.5±6.3	33.2±10.9	0.697
BMI (Kg/m²)	22.9±3.5	22.7±3.3	0.903
Smokers [𝑛 (%)]	8 (53)	5 (33)	0.462
Methimazole [𝑛 (%)]	4 (27)	9 (60)	0.139
OC [𝑛 (% of females)]	6 (50)	5 (45)	1.000
Thyroid volume (mL)	59.5±12.0	64.2±11.7	0.281
24 h-RAIU (%)	78.9±17.3	76.9±11.2	0.719
Basal T4 (nmol/L)	341±121	346±112	0.897
Basal FT4 (pmol/L)	59 (44–89)	60 (49–95)	0.217
Basal T3 (nmol/L)	9.3 (6.0–11.5)	9.6 (5.8–12.9)	0.547
^131I dose (mCi)	16.5±4.2	20.7±3.9	0.008

The values are the mean ± SD or median (25–75%). BMI: body mass index; OC: oral contraceptive; 24 h-RAIU: 24-hour radioiodine uptake.
The reference ranges for laboratory values are T4, 56.3–160.9 nmol/Liter (4.5–12.5 μg/dL); free T4, 8.4–23.2 pmol/Liter (0.6–1.8 ng/dL); and T3, 1.19–2.8 nmol/Liter (78–182 ng/dL).
To convert T4 values to micrograms per dL and free T4 values to nanograms per dL, values should be divided by 12.87. To convert T3 values to nanograms per dL, values are divide by 0.01536.