IODINE WHOLE BODY SCAN, THYROGLOBULIN LEVELS, ~(99m)Tc MIBI SCAN AND COMPUTED TOMOGRAPHY: RESULTS IN PATIENTS WITH LUNG METASTASIS FROM DIFFERENTIATED THYROID CANCER

摘要

Correlation of the ~(131)I whole body scan (~(131)I WBS), ~(99m)Tc-sestamibi (Tc-MIBI) scans, computed tomography (CT) and the value of routine follow-up for ~(131)I WBS and thyroglobulin levels were assessed in patients with differentiated thyroid cancer (DTC) lung metastasis. Pulmonary metastasis was detected with ~(131)I WBS, increased thyroglobulin levels and/or other positive radiological findings in 32 patients out of 583 with DTC. Iodine-131 WBS, thyroglobulin level assessment and/or CT were performed in the diagnosis and follow-up of the patients with lung metastasis. A Tc-MIBI scan was performed on 19 randomly chosen patients. Nineteen out of 32 patients had lung metastasis before they received the first ~(131)I treatment. Pulmonary metastasis was observed in the first ~(131)I WBS of all the patients except one; whereas no pulmonary metastasis was detected in CT in 3/32. The final ~(131)I WBS became normal in 13/32. Thyroglobulin levels diminished in 21/32 and were elevated in 3/32. Iodine-131 WBS continued to be abnormal in 2 out of 3 patients with increased thyroglobulin levels but became normal in 1 patient whose CT still demonstrated macronodulary lesions. Thyroglobulin levels did not change significantly in 8/32. Iodine-131 WBS became normal in 5/8 and 4/5 showed micronodules in their CT scans. Metastasis was detected in 12/19 patients who had Tc-MIBI scans, 18/19 showed metastasis in ~(131)I WBS and 17/19 in CT. Of the 7 patients without the sign of metastasis in Tc-MIBI scintigraphy, 1 was negative in terms of metastasis in ~(131)I WBS and 1 in CT. Fibrosis was observed in 2/32 patients in CT. One patient developed dedifferentiation decided by negative ~(131)I WBS and positive CT. It was concluded that the ~(131)I WBS and thyroglobulin levels are the most important parameters in the evaluation of lung metastasis in DTC. CT is an additional effect to ~(131)I WBS and thyroglobulin level, on the other hand, MIBI imaging alone may not be enough to detect these metastases.