**6.3 Radioablation**

Introduced in the mid-1940s, a relatively inexpensive therapy for treatment of hyperthyroidism, 131I has become the most widely used therapy, although international questionnaire studies show that geographic differences do exist. The isotope being used is 131I. It is given orally (in a capsule or in water) and is absorbed rapidly and completely, after which it is concentrated, oxidised, and organified by follicular thyroid cells. The ionising effect of β-particles, with a path length of 1–2 mm, destroys the thyroid cells by an early inflammatory response, necrosis of follicular cells, and vascular occlusion. Further chronic inflammation and fibrosis result in a decrease in thyroid size and an impaired thyroid function. So most of the patients developed Hypothyroidism following 131I therapy [33].

**53**

*Hyperthyroidism*

**6.4 Dose calculation**

propylthiouracil) [34].

with ophthalmopathy.

**6.6 Pre-operative preparation**

**6.7 Treatment of sub-acute thyroiditis**

for 7–10 days is followed [35].

**7.1 Hyperthyroidism in pregnancy**

**7. Special situation**

**6.5 Surgery**

*DOI: http://dx.doi.org/10.5772/intechopen.90314*

weight (g) ÷ 24 h radioiodine uptake).

Smallest possible dose is preferred so that to make patients euthyroid and avoid permanent hypothyroidism in patients. Dose is calculated by following algorithm: Dose (mCi) = (80 - 200 micro Ci 131I/g thyroid × estimated thyroid gland

With use of above dose calculation algorithm, usual dose patients receive is 5–15 mCi and many become euthyroid followed by hypothyroidism. Dose calculation is time consuming and costly hence fixed dose activity is commonly used in many centres which simplifies and reduces cost of 131I therapy and the lack of a significant difference in outcome between patients randomised to fixed and calculated 131I doses favour the use of fixed doses. Typically a patient with Graves' disease requires 5–15 mCi, 10–29 mCi in patients with toxic nodule and toxic MNG [33]. Not all patients respond to 131I and these patients may require multiple doses at 6–12 monthly intervals. Patients who can be predicted to have poor response are: (1) age (>40 years); (2) Gender (female); (3) severe hyperthyroidism; (4) medium or large goitres (>40 g, visible); and (5) ATD pre-treatment (especially with

Thyroid surgery is oldest available treatment for hyperthyroidism and it's a definitive treatment for the illness. Being an invasive treatment and also associated complications, its least preferred now a days, but indications for the treatment include: (1) patients preference; (2) large size goitres which are causing compressive symptoms or for cosmetic reasons; (3) Graves' disease super imposed on endemic goitre with multiple cold nodules; (4) suspicion of malignancy; and (5) associated

It is mandatory to achieve normal metabolic state before patients undergo thyroid surgery or else patients may land u into thyroid storm. Normal metabolic state is generally achieved by using ATD in appropriate dose and duration. Beta blockers are also used in management to achieve eumetabolism before surgery. Once eumetabolism is achieved SSKI is added, 2–3 drops twice daily, for 7–10 days.

Treatment is usually supportive and symptomatic. Pain is relieved with NSAID's. If pain persists despite maximal NSAID's, prednisolone in a dose of 40 mg per day

Hyperthyroidism is not uncommon during pregnancy with prevalence being 0.1–0.4% of which 80% of the cases are of Grave's disease. The activity level of Graves' disease fluctuate during gestation, with exacerbation during the first trimester and improvement by late gestation related to autoimmune process of

Lugol's iodine can also be used depending on its availability.
