**8. Conclusion**

*Goiter - Causes and Treatment*

**7.2 Medical treatment**

LT4 is not feasible.

**7.3 Radioiodine (I-131)**

without any serious adverse effect [44].

same for toxic and nontoxic MNG. In nontoxic MNG preoperative treatment with

Although most surgeons prefer to do total thyroidectomy, still controversy exists regarding the removal of thyroid tissue in between total and subtotal thyroidectomy for surgical treatment of MNG. In study temporary or permanent recurrent laryngeal nerve palsy, temporary or permanent hypoparathyroidism, hemorrhage, and wound complications were not significantly different in total thyroidectomy versus subtotal thyroidectomy [36]. In an analysis, goiter recurrence was significantly more in subtotal thyroidectomy than total thyroidectomy, but reintervention due to goiter was not significantly higher. Incidence of permanent recurrent laryngeal nerve palsy and permanent hypoparathyroidism was more in the total thyroidectomy group, but it was statistically nonsignificant [37]. Postoperatively serum TSH level should be monitored, many physicians prefer to start thyroid hormone as theoretically this may prevent recurrence of goiter, but studies have not shown this

Levothyroxine (LT4) is used as TSH suppression therapy with variable success for nontoxic goiter. But suppressive therapy with LT4 is associated with thyrotoxicosis particularly in elderly patients. In this subset of patients, it is associated with osteopenia and cardiac arrhythmia and is inversely related to TSH concentration. Very rarely thyroid nodules can become functionally autonomous [40–41]. The goal is to keep TSH in between 0.1 mIU/L and 0.4 mIU/L. However the suppressive therapy is still a matter of debate. A meta-analysis of 11 studies has shown a twofold increase of chance in reduction in nodule size with LT4 suppressive therapy with proper selection of patient [42]. In another study with 54 patients 12 months after starting suppressive therapy, 37.1% of patients with single, solid nodules are found to regress more than 50% in nodule volume, and 20.3% of patients had reduction in nodule volume more than 20% but less than 49.9%. One-third of subjects with MNG had 50% or more regression of the glandular volume, whereas 46.8% were considered as nonresponsive. During suppressive therapy with LT4, the mean serum Tg level was also decreased significantly in these patients [43]. Because of lifelong therapy is required for prevention of goiter recurrence and is associated with risk of autonomous functioning of nodules, so in many patients, TSH suppression with

Antithyroid drugs propylthiouracil and thionamides (carbimazole and methimazole) are used to restore euthyroidism in toxic MNG. They can be used for a long time in patients whom surgery and radioiodine (I-131) treatment are contraindicated. But risk of agranulocytosis remains a major concern. In a recent study, methimazole was used for 8 years in 53 patients for treatment of toxic MNG

Radioiodine (I-131) is in use for management of thyroid disorder for more than 50 years. Radioiodine (I-131) is used particularly for thyrotoxic disorder mainly in Graves' disease. Radioiodine (I-131) also causes a significant reduction of thyroid gland volume. Due to its effect on reduction of thyroid gland volume, it has been used in management of nontoxic nodular thyroid disease also. In one study, 35 patients with nontoxic large MNG were treated with mean 1806 mbq (range 800–4000) of I-131. The mean reduction in thyroid volume was 43.18% (range −17.23–89.66%) seen after 3 months of treatment with I-131 [45]. In another

antithyroid drugs, beta blockers, or potassium iodide is not required.

kind of benefit from thyroid hormone suppressive therapy [38–39].

**106**

MNG is the most common thyroid disorder, but usually it is asymptomatic. When large enough it can cause compression to the trachea, esophagus, and neck veins. Other complications of MNG are autonomous functioning nodules, and very rarely it may progress to malignancy. Diagnostic evaluation includes clinical evaluation, thyroid function, and imaging study. Additional testing with FNAC may be required. Treatment modalities include drugs, surgery, and radioiodine (I-131), depending on results of diagnostic evaluation and associated complications.
