1. Frank P. Dawry Therapy of Hyperthyroid Thyroid Disease with Iodine-131

2. Frank P. Dawry Hyperthyroidism overactivity of the thyroid gland Graves’ disease (Diffuse Toxic Goiter) Most common Most common Autoimmune – thyroid stimulating antibodies interact with TSH-receptor sites on thyroid follicular cell membrane to increase synthesis and secretion of thyroid hormones Autoimmune – thyroid stimulating antibodies interact with TSH-receptor sites on thyroid follicular cell membrane to increase synthesis and secretion of thyroid hormones Characteristics of Graves Disease Characteristics of Graves Disease Graves Disease effects women much more often than men (about 8:1 ratio, thus 8 women get Graves Disease for every man that gets it). Graves Disease effects women much more often than men (about 8:1 ratio, thus 8 women get Graves Disease for every man that gets it). Graves Disease is often called diffuse toxic goiter because the entire thyroid gland is enlarged, usually moderately enlarged, sometimes quite big. Graves Disease is often called diffuse toxic goiter because the entire thyroid gland is enlarged, usually moderately enlarged, sometimes quite big. Graves disease is uncommon over the age of 50 (more common in the 30's and 40's) Graves disease is uncommon over the age of 50 (more common in the 30's and 40's) Graves Disease tends to run in families (not known why) Graves Disease tends to run in families (not known why)

3. Frank P. Dawry Hyperthyroidism overactivity of the thyroid gland Toxic Nodular Goiter (Plummer’s disease) Less frequent Less frequent Thyroid hormone secretion by autonomous areas of increased function within the thyroid gland Thyroid hormone secretion by autonomous areas of increased function within the thyroid gland Thyroiditis (Inflammation of the thyroid gland) Subacute Subacute Hashimoto’s - autoimmune Hashimoto’s - autoimmune

4. Frank P. Dawry Single ‘Hot’ nodule

5. Frank P. Dawry Common symptoms and signs of hyperthyroidism Palpitations Heat intolerance Nervousness Insomnia Breathlessness Increased bowel movements Light or absent menstrual periods Fatigue Insomnia Breathlessness Increased bowel movements Light or absent menstrual periods Fatigue Fast heart rate Trembling hands Weight loss Muscle weakness Warm moist skin Hair loss Staring gaze Fast heart rate Trembling hands Weight loss Muscle weakness Warm moist skin Hair loss Staring gaze

6. Frank P. Dawry Feedback mechanism

7. Frank P. Dawry

8. Common tests used to diagnose hyperthyroidism Thyroid stimulating hormone (TSH) Thyroid stimulating hormone (TSH) Produced by the pituitary gland Produced by the pituitary gland decreased in hyperthyroidism decreased in hyperthyroidism Thyroid hormones themselves (T3, T4) Thyroid hormones themselves (T3, T4) will be increased will be increased Iodine thyroid scan Iodine thyroid scan will show if the cause is a single nodule or the whole gland will show if the cause is a single nodule or the whole gland

9. Frank P. Dawry TREATMENT OPTIONS FOR HYPERTHYROIDISM Anti-Thyroid Drugs - methimazole and propylthiouracil (PTU) interfere with the thyroid gland's ability to make its hormones interfere with the thyroid gland's ability to make its hormones Not a permanent cure Not a permanent cure *Radioactive Iodine Treatment thyroid cells will be damaged or killed thyroid cells will be damaged or killed takes one to two months before the thyroid has been killed takes one to two months before the thyroid has been killed *Surgical Removal of the Gland or Nodule - Lobectomy or Thyroidectomy (partial or total) less frequent use less frequent use Single nodule Single nodule Radioiodine refused Radioiodine refused Anti-thyroid drugs contraindicated Anti-thyroid drugs contraindicated Associated morbidity and mortality Associated morbidity and mortality * Often results in hypothyroidism

10. Frank P. Dawry Hyperthyroid therapy Traditionally <30mCi of I-131 in order to avoid regulatory hospitalization Traditionally <30mCi of I-131 in order to avoid regulatory hospitalization No longer the case since newer NRC release regulations stipulating <500 mrem to other individuals criteria No longer the case since newer NRC release regulations stipulating <500 mrem to other individuals criteria Fixed Millicurie administration Fixed Millicurie administration Graves’ disease 5-10 mCi Graves’ disease 5-10 mCi Nodular disease 10-29 mCi Nodular disease 10-29 mCi Delivered microcuries per gram Delivered microcuries per gram 55 to 160 uCi/gram (Graves’ disease) 55 to 160 uCi/gram (Graves’ disease) 200 uCi/gram (Single Hyperfunctioning autonomous nodule) 200 uCi/gram (Single Hyperfunctioning autonomous nodule) Administered uCi = uCi/gram desired x gland weight (g) x 100/24 hour % uptake Delivered Rad – deliver precise radiation dose Delivered Rad – deliver precise radiation dose >120 Gy (Graves’ disease) >120 Gy (Graves’ disease) 300-400 Gy (Single Hyperfunctioning autonomous nodule) 300-400 Gy (Single Hyperfunctioning autonomous nodule) Administered uCi = Rad desired ( x gland weight (g) x 100/24 hour % uptake x 93)

11. Frank P. Dawry Radiopharmacy Radiopharmacy Oral administration of I-131 sodium iodide capsule or liquid Oral administration of I-131 sodium iodide capsule or liquid Contraindications Contraindications Allergy to Iodine Allergy to Iodine Pregnancy and/or nursing Pregnancy and/or nursing Serum pregnancy test Serum pregnancy test Mechanism of action Mechanism of action Cellular damage caused by the 606keV Beta particle causing chromosomal destruction Cellular damage caused by the 606keV Beta particle causing chromosomal destruction

12. Frank P. Dawry Beta Particle Therapy

13. Frank P. Dawry Patient Preparation Prior to administration Prior to administration Identify patient Identify patient Verify doctor’s orders Verify doctor’s orders Explain the procedure Explain the procedure Patient off of thyroid medications for at least 2 days Patient off of thyroid medications for at least 2 days Ensure that no iodinated radiographic studies within the past 3 weeks Ensure that no iodinated radiographic studies within the past 3 weeks Ensure that a negative result to a recent serum pregnancy test has been received! Ensure that a negative result to a recent serum pregnancy test has been received!

14. Frank P. Dawry Patient Preparation A written consent form should be obtained and should mention the following items: A written consent form should be obtained and should mention the following items: that more than one I-131 treatment may be necessary that more than one I-131 treatment may be necessary the risk of eventual hypothyroidism is high, especially after treatment of Graves’ disease the risk of eventual hypothyroidism is high, especially after treatment of Graves’ disease lifelong daily ingestion of a thyroid hormone tablet would be necessary lifelong daily ingestion of a thyroid hormone tablet would be necessary long-term follow-up will be necessary long-term follow-up will be necessary ophthalmopathy may worsen or develop ophthalmopathy may worsen or develop rarely, there can be transient neck soreness or exacerbation of hyperthyroid symptoms secondary to radiation thyroiditis rarely, there can be transient neck soreness or exacerbation of hyperthyroid symptoms secondary to radiation thyroiditis

15. Frank P. Dawry Patient Preparation After administration discharge instructions After administration discharge instructions Instruct patient to avoid close contact with anyone for 48 hours Instruct patient to avoid close contact with anyone for 48 hours Instruct patient not to share food or utensils – do not use disposable plates and utensils Instruct patient not to share food or utensils – do not use disposable plates and utensils Flush two to three times Flush two to three times Wash clothes and linens separately – double rinse Wash clothes and linens separately – double rinse Inform patient that they may feel a scratchy throat Inform patient that they may feel a scratchy throat Inform patient that the effect may be delayed for a week or more Inform patient that the effect may be delayed for a week or more Instruct patient to contact the department immediately if dose is vomited* Instruct patient to contact the department immediately if dose is vomited* *the patient ideally should remain in the department for one hour following administration

16. Frank P. Dawry Bioassay Florida State Regulation: 64E-5.625 Safety Instruction and Precautions for Radiopharmaceutical Therapy, Brachytherapy, and Teletherapy. Florida State Regulation: 64E-5.625 Safety Instruction and Precautions for Radiopharmaceutical Therapy, Brachytherapy, and Teletherapy. measure the thyroid burden of each individual who helped prepare or administer a dosage of liquid iodine 131 within 3 days after administering the dosage. measure the thyroid burden of each individual who helped prepare or administer a dosage of liquid iodine 131 within 3 days after administering the dosage. Nuclear Regulatory Commission, Part 35 Nuclear Regulatory Commission, Part 35 requires that, for staff who helped prepare or administer a dosage of 131I to patients who were hospitalized for compliance with the patient-release criteria, a measurement of thyroid burden must be made within three days of such administration. requires that, for staff who helped prepare or administer a dosage of 131I to patients who were hospitalized for compliance with the patient-release criteria, a measurement of thyroid burden must be made within three days of such administration.