False positive radioiodine uptake in the eye, detected on SPECT/CT whole-body scan: The importance of using hybrid imaging

Document Type : Case Report

Authors

1 Department of Nuclear Medicine, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran

2 Student Research Committee, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran

Abstract

False positive radioiodine uptake may pose difficulties in diagnosis and subsequent management of thyroid cancer. Combined imaging techniques, such as SPECT/CT, play a crucial role in accurately identifying the specific location of radioiodine uptake, thereby avoiding potential diagnostic error. This is particularly important in situations where unexpected uptake could lead to unnecessary treatment interventions such as surgery or radioiodine treatment. In this study, we discuss a case involving a 38-year-old female with a history of thyroid cancer and I-131 treatment. Approximately six years later, her course was complicated by left sided epiphora leading to dacryocystorhinostomy and subsequently elevation of thyroglobulin (Tg) levels prompting retreatment by radioiodine.  The post-therapy whole-body scan revealed false-positive radioiodine uptake on the left side of the skull, conclusively confirmed through SPECT/CT imaging to be localized in the patient's left eye.

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