False-Positive Radioiodine Scans in Thyroid Cancer.

The whole-body radioiodine scan remains an important component in the postoperative treatment of patients with well-differentiated thyroid cancer. Because normal thyroid tissue remnants and residual or metastatic foci of well-differentiated thyroid cancer have the unique ability to concentrate, organify, and store radioiodine, the wholebody scan provides a depiction of those tissues that can be ablated with therapeutic doses of radioiodine. Over time, it has become obvious that the whole-body scan may also reveal foci of radioiodine accumulation from a wide variety of other causes. This chapter provides an update of an article in the Seminars of Nuclear Medicine* in 2000 that detailed the pathophysiological classification of artifacts, anatomic and physiological variants, and nonthyroidal diseases that may give rise to false-positive whole body scans in postoperative patients with thyroid cancer. [ABSTRACT FROM AUTHOR]