Thyroid cancer, treatment

The goal in thyroid cancer treatment is to optimize iodine uptake. A number of different strategies and agents have been used to stimulate NIS expression and iodine uptake in refractory thyroid cancer, although TSH remains the most potent stimulus. 

Remnant ablation with following surgical resection of the thyroid is considered standard clinical care in thyroid cancer treatment. The optimal dose required to achieve successful ablation remains controversial. 

Iodine-131 is useful in the treatment of thyroid cancer and has a t1/2 of 8 days. How long would it take to decay to 25% of its original amount ... 

If only multiples of half-lives are considered, the calculations are very straightforward. For example, 1-131 is used in the treatment of thyroid cancer and has a tu2 of eight days. How long would it take to decay to 25% of its original amount Looking at the chart, you see that 25% decay would occur at two half-lives or 16 days. However, since radioactive... 

Radiotherapy is a local treatment aiming to achieve local control or cure of locally confined tumours. It cannot treat metastases. Radiotherapy may be administered as external beam radiotherapy with X-rays or gamma rays, in sealed radioactive sources (e.g. prostate brachytherapy), or unsealed sources (e.g. orally administered radioiodine for thyroid cancer, intravenous strontium-89 for bone metastases). In external beam radiotherapy, the X-ray or gamma ray beams are targeted at the tumour to damage and kill the tumour cells. Inevitably, surrounding normal tissues are also affected resulting in the early and late side effects of radiotherapy. 

Pituitary TSH suppressants In the treatment or prevention of various types of euthyroid goiters, including thyroid nodules, subacute, or chronic lymphocytic thyroiditis (Hashimoto), multinodular goiter, and in the management of thyroid cancer (except liothyronine). 

In the treatment of well-differentiated (papillary and follicular) thyroid cancer, levothyroxine is used as an adjunct to surgery and radioiodine therapy. Generally, TSH is suppressed to less than 0.1 milliunits/L, and this usually requires a levothyroxine dose of greater than 2 mcg/kg/day. However, in patients with high-risk tumors, the target level for TSH suppression may be less than 0.01 milliunits/L. 

Iodine is an essential nutrient element required for thyroid gland. It is added to salt and to animal feeds for the prevention of goiter. In medicine it is used as a therapeutic reagent for the treatment of various thyroid-related diseases. It also is used as an antiseptic. Radioactive isotopes of iodine are used for treating thyroid cancer, heart diseases including tachycardia, and as a tracer for diagnosing certain diseases. 

TSH is approved for medical use as a diagnostic aid in the detection of thyroid cancer/thyroid remnants in post-thyroidectomy patients. Thyroid cancer is relatively rare, exhibiting the highest incidence in adults, particularly females. First-line treatment is surgical removal of all or most of the thyroid gland (thyroidectomy). This is followed by thyroid hormone suppression therapy, which entails administration of T3 or T4 at levels sufficient to maintain low seum TSH levels through the negative feedback mechanism mentioned earlier. TSH suppression is required... 

Detection/treatment of thyroid cancer hGH deficiency in children... 

Therapeutic Techniques. Probably the most prominent therapeutic use of radiopharmaceuticals is radioactive iodine in the treatment of metastatic thyroid cancer. 131I has a half-life of about 8 days and emits gamma and beta rays. When iodine salts are taken into the body, most of the dose is concentrated in the thyroid gland. A dose of radioactive iodine salt similarly concentrates in the thyroid gland. When there is a cancer in the thyroid gland, or the gland is overactive (hyperthyroidism), the excessive... 

The administration of 131I requires safety measurements to reduce to a minimum the irradiation of medical personnel and to avoid contamination of rooms and relatives of patients. Capsules containing 131I are therefore to be preferred to liquid iodine. At doses above 25 mCi (555 MBq), usually intended only for treatment of patients with thyroid cancer, isolation in a specially constructed room of a service for nuclear medicine is necessary. Waste disposal should also be carefully managed so as to avoid overall contamination (5,6). 

Leukemia does not occur more often in patients treated with 131I for hyperthyroidism than in similar patients treated by surgery. After use of the high doses used in the treatment of thyroid cancer there was a definite increase in the incidence of leukemia (18). 

Table 2 1311 treatment and thyroid cancer a comparison with thyroidectomy and antithyroid drugs... 

Thyrotropin stimulates iodine uptake, and this facilitates the diagnosis and treatment of recurrent disease or metastases in the follow-up of differentiated thyroid cancer. It is used as an alternative to thyroid hormone withdrawal, to avoid symptomatic hypothyroidism (1). Headache and nausea occur in 6-40% of patients after intramuscular administration, but are usually mild and transient (2,3). 

Pichert G, Jost LM, Zobeli L, Odermatt B, Pedia G, Stahel RA. Thyroiditis after treatment with interleukin-2 and interferon alpha-2a. Br J Cancer 1990 62(l) 100-4. 

Treatment of metastatic differentiated thyroid cancer requires the administration of large doses of 131I (30-200 mCi) in the presence of persistently high serum levels of TSH (see Chapter 38 Thyroid Antithyroid Drugs). Patients must withdraw from thyroid hormone replacement in order to achieve this. For treatment purposes, thyrotropin alpha administration cannot substitute for thyroid hormone withdrawal. 

Thyroid receptor agonists consisting of thiazolidine-2,4-dione derivatives, (I), were prepared by Chiang (1) and used in the treatment of thyroid diseases including hypothyroidism and thyroid cancer. 

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