I. Purpose

The purpose of this guideline is to assist nuclear medicine practitioners in recommending, per-forming, interpreting, and reporting the results of extended scintigraphy for differentiated thyroid cancer. II. Background Information and Definitions Scintigraphy for detection of thyroid metastasis and/or residual functioning thyroid tissue consists of obtaining images of the body, 2–6 days following the oral ingestion of I-131. Other radiopharmaceuti-cals such as I-123, Tl-201 and Tc-99m sestamibi may also provide useful information. III. Common Indications To determine the presence and extent of residual functioning thyroid tissue and the presence and lo