TY - JOUR T1 - All That Glitters Is not Gold: Peals and Pitfalls in I-131 Scans for Differentiated Thyroid Cancer JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 989 LP - 989 VL - 58 IS - supplement 1 AU - Francisco Lazaga AU - Salil Sharma AU - Pranav Sharma AU - Scott Williams Y1 - 2017/05/01 UR - http://jnm.snmjournals.org/content/58/supplement_1/989.abstract N2 - 989Objectives: 1. To discuss the normal thyroid physiology and current indications for I-131 scan in differentiated thyroid cancer (DTC). 2. Illustrate the normal physiologic bio-distribution of I-131 including cases of physiologic liver uptake, thymic uptake and swallowed esophageal uptake. 3. To describe possible false positive scans secondary to pathologic uptake unrelated to thyroid cancer including sample cases of iodine avid tumor thrombus, stroke, liver cysts, and inflammation, and liver cysts. 4. To emphasize on possible false negative scans including sample cases such as thyroid stunning. 5. To demonstrate how to work up such possible false positive and false negative cases including correlative multimodality imaging when needed. 6. Additional interesting cases will be displayed including: -Hurthle cell Neoplasm negative on I-131, but positive on thallium. -Bone met negative on I123, but positive on I131 -Bone met negative on bone scan, but positive on I131 -Diffuse lung metastases -Brain, adrenal and spinal metastases. - Thyroid lymphomaMethods: A collection of I -131 scans including false positive and false negative cases of physiologic thymic, liver, and esophageal uptake as well as uptake related to tumor thrombus, stroke, inflammation secondary to burns and pneumonitis, and liver cysts will be displayed along with correlative CT, MRI, SPECT, SPECT/CT, etc. Guidelines for the further work up and management of unusual uptake will be discussed. Review of the literature will be performed based on nonpathologic and pathologic I-131 uptake unrelated to thyroid cancer.Results: N/AConclusion: We review thyroid gland physiology and describe a systemic overview of potential false positive and false negative lack of uptake of radioiodine in the whole body along with illustrations and cases. By understanding the physiology and characteristics of radioiodine uptake and correlating with anatomical imaging, biochemical data, and clinical findings, physicians can be more confident in establishing proper management for patients with DTC using radioiodine whole body scans. Research Support: N/A ER -