Clinical utilization of Iodine I131 in diagnostic in Nuclear Medicine :Presented by: Gustavo Thondik Clinical utilization of Iodine I131 in diagnostic in Nuclear Medicine


Objectives :Objectives Illustrate how Iodine can be radioactive Characteristic of I131 Radiopharmaceuticals Show how chemicals can block the thyroid Discuss nuclear studies with radioactive iodine Illustrate normal and abnormal results iodine studies in nuclear medicine.


Radioactive Iodine :Radioactive Iodine There are non radioactive and radioactive forms of iodine. Most radioactive iodine is manmade. I131 is made in a nuclear reactor and it is a waste product of this reactor. It decays by electron capture I123 is made in a cyclotron and some of its waste products are I125 and I124. They are used in medical tests and to treat certain diseases.


I-131 Characteristics :I-131 Characteristics Atomic number: 53 Neutrons: 78 Atomic Weight: 126.90447(3)  g·mol−1 Half life: 8.0197 days with beta and gamma emissions Energies: 364 keV Decay:


Radio Pharmaceuticals of I-131 :Radio Pharmaceuticals of I-131 Na I131 (Sodium iodine131) Thyroid Uptake Dose: 1 uCi to 10 mCi Thyroid Ablation Dose: 30 to 300 mCi Hyperthyroidism Therapy Dose: 1 to <30 mCi Whole body scan (ectopic metastatic thyroid tissue) Dose: 1 to 5 mCi Tumor Dose: 5 to 10 mCi


Nuclear Iodine Exams :Nuclear Iodine Exams Whole Body 131 scan Thyroid scan with I 131 is shown above but since the dose is so small due to its high KeV, the images have poor resolution


Radio Pharmaceuticals of Iodine :Radio Pharmaceuticals of Iodine I131-NP59 used to image adrenal cortex Where cortisol is produced , which is a precursor of estrogen, testosterone, and progesterone. Too much cortisol produce is known as Cushing’s syndrome Dose: 2 mCi I131-mIBG ( iodomethylnorcholesterol) used to imaging Adrenal Cortex Use to locate tumor in the adrenal cortex(adenomas tumor)


Radio Pharmaceuticals of Iodine :Radio Pharmaceuticals of Iodine I131-mIBG ( meta-iodobenzylguanidine) used to imaging Adrenal Medulla: Pheochromocytoma Dose: 1 mCi Where epinephrine is produce, which is adrenaline Epinephrine is a vasoconstrictor, which is a bronchio-dilator I131 Bexxar (tositumomab) Monoclonal antibody therapy to treat auto immune disease such as Graves disease (Hyperthyroidism) , non-Hodgkin’s lymphoma, and systematic lupus erythocytosis.


Slide 10:I131-OIH ( orthoiodohippurate) used to imaging Kidneys Hippuran : Use for renal and glomerular tubes


Images Thyroid scan & uptake :Images Thyroid scan & uptake


Blocking the thyroid :Blocking the thyroid When doing a nuclear exam with Iodine radioisotopes the thyroid should be blocked with: Potassium Iodide Some exams use potassium iodine as: Adrenal glands & Salivary glands.


Instrumentation of Iodine studies in nuclear medicine :Instrumentation of Iodine studies in nuclear medicine Equipment: Camera: use a large field of view Collimator: HERS, or Pinhole Computer set up: I123 scan & I131 Marker, Anterior, RAO, LAO (static images)


Thyroid Scan Procedure :Thyroid Scan Procedure I131 capsule Images taken at 24 hr after ingestion Supine position Taking images with/ without markers Camera centered over thorax


Indication for Thyroid scan :Indication for Thyroid scan Evaluation of thyroid anatomy ( goiter) Treatment of Grave’s disease (thyrotoxicosis diffuse toxic goiter) Detection or evaluation of hyperthyroidism and hypothyroidism Detection of metastases from cancer Evaluation of thyroid after abnormal finding in PET, CT, MRI


Contraindication for thyroid scan :Contraindication for thyroid scan Allergy to iodine With iodine, interfering recent contras studies


Hyperthyroid Therapy procedure :Hyperthyroid Therapy procedure Scan uptake within 2 weeks Obtain consent form from pt Obtain written prescription before ordering the doses Provide a glass of water to pt Inform pt of evaluation in 2 to 3 month Be sure pt does no vomit capsule


Indication for hyperthyroidism therapy :Indication for hyperthyroidism therapy Treatment of hypothyroidism Treatment of Grave’s disease (thyrotoxicosis, diffuse toxic goiter) Treatment of toxic nodular goiter


Contraindications :Contraindications Pregnancy Allergy of iodine Interfering iodine medications Interfering food source


Whole body thyroid cancer procedure :Whole body thyroid cancer procedure Supine position Remove attenuating articles Instruct pt to remain motionless Images at 72 hr (optional at 24/ 48 hrs) Whole body statics (10 min/image)


Indication :Indication Evaluation of thyroid carcinoma Evaluation and localization of thyroid tissue


Contraindications :Contraindications Allergy to iodine Iodine radiographic studies High-iodine diet Taking thyroid medication


Adrenocortical Scan procedure :Adrenocortical Scan procedure I131-6-β (NP-59) Begin imaging 5 days after injection Supine position, camera posterior and kidney centered Static 100,000 counts or 5-20 min Lateral and posterior views Record percent uptake Determine if SPECT images need


Indications :Indications Detection and localization of adrenal glands Detention of abnormal function in adrenocorticotropic hormone ACTH Evaluation primary hyperaldosteronism Evaluation for surgical intervention


Contraindications :Contraindications Allergy to iodine Patient taking interfering medications


Adrenal Medulla Procedure :Adrenal Medulla Procedure I131-mIBG Empty bladder Supine position Acquire anterior/posterior images of head, neck, thorax, abdomen, pelvis Static images 100,000 counts Use 5 uCi capsule Acquire SPECT if need


Indications :Indications Detection of benign and malignant tumors Localization of hormonal overproduction Localization of nerve tissue tumors Detection of medullar thyroid tumors Evaluation of surgery


Contraindications :Contraindications Allergy of iodine Patient taking interfering medications


Summary :Summary I131 is made in a nuclear reactor and is a waste product of it. It decays be electron capture Radio Pharmaceutical of Iodine: Na I131 (Sodium iodine131) I131-NP59 I131-mIBG ( meta-iodobenzylguanidine) I131 Bexxar (tositumomab) Potassium Iodide


Summary (cont) :Summary (cont) Radiopharmaceutical of Iodine is applied to different diagnose in NM as: Thyroid Uptake Thyroid Ablation Hyperthyroidism Therapy Tumor Adrenal cortex Adrenal Medulla Treating of immune diseases


Question 1 :Question 1 Define Graves Disease


Answer 1 :Answer 1 Graves Disease: Thyrotoxicosis, diffuse toxic goiter


Question 2 :Question 2 Name the Radio Pharmaceutical of Iodine


Ansqer 2 :Ansqer 2 Radio Pharmaceutical of Iodine: Na I131 (Sodium iodine131) I131-NP59 I131-mIBG ( meta-iodobenzylguanidine) I131 Bexxar (tositumomab) Potassium Iodide


Question 3 :Question 3 How is made I131?


Answer 3 :Answer 3 I131 is made in a nuclear reactor and it is a waste product of this reactor


Question 4 :Question 4 What radiopharmaceutical are used to image adrenal cortex?


Answer 4 :Answer 4 I131-NP59 and I131-mIBG are used to image adrenal cortex


Question 5 :Question 5 T/F Iodine-131 Bexxar (tositumomab) is a monoclonal antibody therapy used to treat auto immune disease such as Graves disease, non-Hodgkin’s lymphoma, and systematic lupus erythocytosis.


Answer 5 :Answer 5 True


Question 6 :Question 6 When doing a nuclear exam with Iodine radioisotopes, how thyroid should be blocked?


Answer 6 :Answer 6 When doing a nuclear exam with Iodine radioisotopes the thyroid should be blocked with: Potassium Iodide


Question 7 :Question 7 T/F The thyroid scan procedure include: I131 capsule Images taken at 24 hr after ingestion Supine position Taking images with/ without markers Camera centered over thorax


Answer 7 :Answer 7 True


Question 8 :Question 8 T/F I131 is made in a cyclotron


Answer 8 :Answer 8 False


Question 9 :Question 9 Name some of contraindications of Iodine I-131


Answer 9 :Answer 9 Contraindications of Iodine I-131: Pregnancy Allergy of iodine Interfering iodine medications Interfering food source


Question10 :Question10 T/F Iodine I131-mIBG ( iodomethylnorcholesterol, an analog of cholesterol) It is used to imaging Adrenal Cortex and to locate tumor in the adrenal cortex, as adenomas tumor


Answer 10 :Answer 10 True


References :References http://en.wikipedia.org/wiki/Iodine radiology.duke.edu/wysiwyg/downloads/Thyroid_Scan.ppt http://www.libreriauniversitaria.it/nuclear-medicine-technology-procedures-and/book