Click here for Frequently Asked Questions on a Toxic Multinodular Goiter.
A multinodular goiter is simply a thyroid gland that is usually enlarged and contains multiple thyroid nodules. The nodules can be very small, often only a few millimeters in size, or the nodules can be larger, perhaps several cm each. There are generally two questions that need to be answered in patients with a multinodular goiter. The first question is usually: are all the nodules benign? The approach to this question depends on the clinical presentation, associated risk factors, the size of the nodules, and whether the nodules are functioning or non-functioning. An overview of diagnostic and treatment considerations for patients with a large thyroid (goitre) can be reviewed at Approach to the patient with nontoxic multinodular goiter. J Clin Endocrinol Metab. 2011 May;96(5):1202-12
Non-functioning or cold nodules within a multinodular gland generally carry the same risk of malignancy as a single isolated cold nodule (10-15% risk of thyroid cancer) and need to be approached diagnostically in a similar manner akin to the investigation of an isolated single cold nodule.
The second question that needs to be answered relates to ascertainment of thyroid function in patients with a multinodular gland, as these patients often exhibit mild to moderate degrees of hyperthyroidism.
If treatment of a multinodular goiter is indicated, radioactive iodine or surgery is generally more effective in achieving a long-lasting solution to the problem compared to the use of medications alone. Although the hyperthyroidism may be treated initially with antithyroid medications, these medications will not usually achieve a permanent remission in patients with a multinodular goiter and hyperthyroidism.
Many patients with a toxic goiter may not have elevated levels of radioactive iodine uptake, rendering treatment with this modality challenging. It may be possible to use recombinant TSH to stimulate radioactive iodine uptake in this subgroup of patients. See Effect of various doses of recombinant human thyrotropin on the thyroid radioactive iodine uptake and serum levels of thyroid hormones and thyroglobulin in normal subjects. J Clin Endocrinol Metab. 2001 Apr;86(4):1660-4. The available evidence suggests that low dose (0.3 mg) Thyrogen improves the reduction in thyroid volume and treatment efficacy in subjects receiving radioactive iodine for the treatment of multinodular goitre Prestimulation with Recombinant Human Thyrotropin (rhTSH) Improves the Long-Term Outcome of Radioiodine Therapy for Multinodular Nontoxic Goiter J Clin Endocrinol Metab. 2012 May 10. [Epub ahead of print]
Furthermore, current research protocols are assessing whether lower doses of Recombinant TSH, perhaps 0.03mg, and perhaps lower doses of radioactive iodine, can be used as an adjunct to increase iodine uptake during treatment of toxic goitre as described in Low-dose recombinant human thyrotropin-aided radioiodine treatment of large, multinodular goiters in elderly patients. Eur J Endocrinol. 2006 Feb;154(2):243-52 and Stimulation with 0.3-mg recombinant human thyrotropin prior to iodine 131 therapy to improve the size reduction of benign nontoxic nodular goiter: a prospective randomized double-blind trial. Arch Intern Med. 2006 Jul 24;166(14):1476-82. and Stimulation with 0.3-mg recombinant human thyrotropin prior to iodine 131 therapy to improve the size reduction of benign nontoxic nodular goiter: a prospective randomized double-blind trial. Arch Intern Med. 2006 Jul 24;166(14):1476-82 and Radioiodine (131)I Treatment for Large Nodular Goiter: Recombinant Human Thyrotropin Allows the Reduction of Radioiodine (131)I Activity to Be Administered in Patients with Low Uptake. Thyroid. 2011 May 13. [Epub ahead of print]
My Free T4 is normal, my TSH is low, and I feel fine, yet my physician wants to treat me with radioactive iodine. Why?
The answer to this question depends on the age of the patient, the size of the gland, the associated medical conditions that may be present, the extent of hyperthyroidism, and this issue needs to be discussed carefully between physician and patient. In some instances, particularly in older individuals or in the potential setting of heart disease, it is sometimes advisable to treat a patient before an obvious clinical problem becomes apparent, such as the development of an unstable and rapid heart rhythm.
I have a large goitre and borderline high levels of thyroid hormones (mild hyperthyroidism). What are the treatment options?
Traditionally, treatment of patients with large multinodular goitres may include surgery, or radioactive iodine. Not all patients with large goitres have sufficient iodine uptake to allow for effective therapy with radioactive iodine. In some instances, adjuvant use of low dose recombinant TSH may increase iodine uptake in the thyroid and allow for more efficient treatment with radioactive iodine, as described in Low-dose recombinant human thyrotropin-aided radioiodine treatment of large, multinodular goiters in elderly patients. Eur J Endocrinol. 2006 Feb;154(2):243-52
Is there any risk to treatment of a multinodular goitre with radioactive iodine?
experience some degree of neck discomfort and swelling in the region of
the thyroid gland following radioactive iodine. Furthermore, destruction
of thyroid tissue is often associated with transient worsening of the
hyperthyroidism for a few weeks, and in elderly subjects with a history of
heart disease, this can be a serious issue. There is some evidence that
older subjects treated with radioactive iodine may have an increased risk
of mortality, but not if the treatment is sufficiently effective so as to
Increased cardiovascular and cancer mortality after radioiodine treatment
for hyperthyroidism. J
Clin Endocrinol Metab. 2007 Mar 20; [Epub ahead of print]
Can recombinant TSH be used to treat hyperthyroidism associated with a multinodular goitre?
There is some evidence that using a low dose of Thyrogen may result in enhanced uptake of radioactive iodine and thereby permit lower doses of radioactive iodine to be used, however this approach clearly requires more study Recombinant Human Thyrotropin-Stimulated Radioiodine Therapy of Nodular Goiter Allows Major Reduction of the Radiation Burden with Retained Efficacy J Clin Endocrinol Metab. 2010 Jun 2. [Epub ahead of print]