[Indication for iodine-123 in scintigraphy of the thyroid gland]

Diagnostic work-up of a coincidental finding of a mediastinal tumour in asymptomatic patients should initially be done by non-invasive imaging modalities. We present a case in which traditional use of 99mTc pertechnetate scintigraphy was insufficient in a male with an enlarged thyroid gland. Application of iodine-123 can show diagnostic superiority owing to ideal tracer properties for scintigraphic imaging of the thyroid gland, such as pure gamma emission, organic binding and slow wash-out. The cons are a high radiation burden, price and lack of availability, as iodine-123 is a cyclotron product.