Usefulness of SPECT/CT for equivocal findings on (131)I whole-body scan in a patient with differentiated papillary thyroid cancer.

A 42-year-old female patient who underwent right central compartment node dissection owing to recurrence of differentiated papillary thyroid carcinoma received 150 mCi of I as an adjuvant therapy. Uptake was observed at the thyroid bed and right lower neck, suggesting thyroid remnant tissues and/or lymph node metastasis on a whole-body scan obtained 5 days after I administration. SPECT/CT was performed and the uptake at the right lower neck was finally diagnosed as a lung metastasis. This case illustrates the benefit of SPECT/CT for a patient with equivocal findings on an I planar image.