Thyroid - Diseases & Treatment

   Thyroid gland secretes the major hormones T3 (triiodothyronine) & T4 (thyroxine) which are  very important in our body metabolisms (stimulates a conversion process of oxygen & nutrients into energy). Iodine is vital for the normal function of the thyroid gland.

   The common diseases related to the thyroid gland are:

1. Hypothyroidism: underactive thyroid gland.

2. Hyperthyroidism: overactive thyroid gland.

3. Thyrotoxicosis: excess production of thyroid hormones.

4. Thyroid storm: life threatening due to excessive thyroid hormones.

5. Thyroid cancer: an abnormal growth rate of thyroid cell/tissue.

   When the thyroid is overactive (hyperthyroidism) or develops cancer, radioactive I-131 is given for killing thyroid cells.  Iodine is trapped & organified by only thyroid cells with just small amount goes into gastrointestinal & urinary system.

   Normally, a treatment for hyperthyroidism & thyroid cancer is either by one or combination of these; drug medication, surgery (thyroidectomy) & radioiodine ablation. Not even a single surgeon can claim he/she could perform a real full thyroidectomy. There will be some remnant tissue left. This remnant tissue must be treated (ablated) using I-131 (75-150mCi/g of thyroid). A normal dose (activity) for hyperthyroidism is <30 mCi while for thyroid cancer is 30-200 mCi.

   Any thyroid medication must be stopped (carbimazole: 7 days/thyroxine: 4 weeks) prior to scanning/treatment. Patient must fast at least for 4 hours before the procedure in order to enhance the absorption of I-131. Fasting can also prevent patient from vomiting (& thus reduce a possibility of I-131 contamination).

   Prior to I-131 scanning/therapy,  patient must not take any iodine-containing foods such as vitamins containing iodine, iodized salt, sea fish & shellfish, seafood, canned fruits/vegetables, tea  & lemonade.

   A few days after receiving I-131, patient normally tends to have one or all of these:

a.    neck tenderness.

b.    dry mouth.

c.    nausea, sore throat, & vomiting.

d.    salivary glands may swell. 

   Breast-feeding or fathering children is strictly must be stopped for 6 months after I-131 treatment. This treatment is also not recommended for a pregnant or nursing woman & pregnancy should be delayed for at least 6-12 months after receiving treatment. It can affect fertility in men too.