TG and metastatic neoplasm: In the remaining one, metastatic disease was detected by a CT scan performed after one treatment with RAI with WBS showing only small cervical uptake (but non-suppressed Tg levels). Among the five patients with distant metastases, four were located in the lung only and one had them in the lung, liver, and bone (this patient had been exposed to large amounts of radiation during various cardiac catheterizations performed due to a congenital heart defect).