Table 4 Result of primary studies

Namwongprom et al. [26]

2021

Retrospective Cohort

Radioiodine: 24 h I-131

Hypothyroidism achieved 3–6 months after treatment in 65.6% of participants after single dose I-131

NA

H Lee et al. [27]

2021

Retrospective

cohort

Methimazole (MMI)

Free thyroxine levels returned to normal after a mean time of:

• 5.64 weeks for an initial dose of < 0.4 mg/kg/day (Group A)

• 8.61 weeks for an initial dose of < 0.4-0.7 mg/kg/day (Group B)

• 7.98 weeks for an initial for an initial dose of > 0.7 mg/kg/day (Group C)

Liver dysfunction (ALT/AST > 60IU/L)

Group A vs. B vs. C: P = 0.034

No events of serious liver failure

Neutropenia (neutrophil count < 1000/mm3

Group A vs. B vs. C: P = 0.015

No agranulocytosis

Song et al. [28] 2021

Retrospective cohort

Methimazole (MMI) or Propylthiouracil (PTU)

More than six months of euthyroid status after terminating ATD treatment was defined as achieving remission.

Cumulative remission rates:

• Within 1 year of starting ATD = 3.3%

• Within 3 years of starting ATD = 19.6%

• Within 5 years of starting ATD = 34.1%

• Within 7 years of starting ATD = 43.5%

• Within 10 years of starting ATD = 50.6%

Total adverse events = 13.3%

Most common:

• Rash = 5.6%

• Abnormal CBC = 2.6% (neutropenia), 0.5% (agranulocytosis)

• Abnormal LFTs = 2.1% (↑ liver enzymes, no fulminant failure)

Mizokami et al. [29]

2020

Retrospective cohort

Radioiodine:

I-131

Outcomes of thyroid levels:

• Overt hypothyroidism = 91%

• Subclinical hypothyroidism = 2%

• Euthyroidism = 5%

• Subclinical hyperthyroidism = 2%

Adverse events reported included:

• Thyroid cysts = 4.27%

• Iso-or hypo-echoic solid nodule(s) = 7.69%

• 17.5% of patients followed up for 10 years or more developed newly detected solid thyroid nodules