J Korean Soc Endocrinol.  1998 Dec;13(4):572-579.

Technetium-99m sestamibi whole Body Scintigraphy in Postoperative Follow-up of Differentiated Thyroid Carcinoma

• Kim HK
• Kim ES
• Song YK
• Ryu JS
• Moon DH

Abstract

BACKGROUND: Recently technetium-99m sestamibi (99mTc MIBI), which dose not require withdrawal of thyroid hormone, has been used for imaging of thyroid carcinoma. The aim of this study was to determine the clinical usefulness of Tc MIBI scintigraphy after total thyroidectomy for thyroid carcinoma. The results were compared with those of standard 131I scintigraphy.
METHODS
One hundred twelve patients with a median age of 44 years (range, 14-76 years) were included in the study. After optimal endogenous thyroid stimulating hormone stimulation (>50 mIU/mL), whole body scintigraphy using 4 mCi of 'I and 20 mCi of Tc sestamibi were done simultaneously. Concomitantly serum thyroglobulin and anti-thyroglobulin antibody levels were checked. If abnormal findings on any of the scintigraphic methods or high levels of thyroglobulin (> 10ng/mL) were detected, diagnostic imaging studies were done to confirm the existence of the disease. And high dose (150-200 mCi) 'I was administered as therapy and then whole body scans were performed again after the therapy. The presence or absence of thyroid cancer was established by pathologic, radiologic, and/or high dose I scan findings.
RESULTS
In 11 patients, Tc MIBI scan revealed positive accumulations which were not found on 131I scan, of whom 6 had elevated thyroglobulin levels. In these cases, 5 cases were interpreted to have normal thyroid remnant and 6 cases showed pathologic findings (2 lung, 1 lymph node, 1 lung and lymph node, 1 local recurrent cancer, and 1 false positive accumulation of 99mTc MIBI). Metastasis or residual cancer were confirmed histologically in 1 and radiologically in 4 cases. Negative 99mTc MIBI scans, despite of positive I scans, occurred in 9 patients, of whom 2 had abnormal thyroglobulin levels. Seven cases were interpreted to have thyroid remnant, 2 cases were confirmed to have lung metastasis, and another one was misinterpreted due to breast shadow.
CONCLUSION
In conclusion, these results suggest that 99mTc MIBI scan may have similar sensitivity and specificity for the detection of residual or metastatic differentiated thyroid carcinoma. The 99mTc MIBI scan, especially in cases of negative 131I scan despite of abnormal thyroglobulin levels, can be used as a very useful complementary diagnostic tool.

MeSH Terms

Breast
Diagnostic Imaging
Follow-Up Studies*
Humans
Lung
Lymph Nodes
Neoplasm Metastasis
Neoplasm, Residual
Radionuclide Imaging*
Sensitivity and Specificity
Technetium Tc 99m Sestamibi
Thyroglobulin
Thyroid Gland*
Thyroid Neoplasms*
Thyroidectomy
Thyrotropin
Whole Body Imaging
Technetium Tc 99m Sestamibi
Thyroglobulin
Thyrotropin