Sensitivity of [99mTc]methoxyisobutylisonitrile scan in patients with metastatic differentiated thyroid cancer.
OBJECTIVE
The aim of the present study was to evaluate the diagnostic sensitivity of [(99m)Tc]methoxyisobutylisonitrile ([(99m)Tc]MIBI) in a large series of patients with metastatic differentiated thyroid carcinoma (DTC), as compared with (131)I-whole body scan (WBS) and other diagnostic imaging techniques.


METHODS
Eighty-four patients with known metastases from DTC where recruited during the course of replacement thyroxine therapy and undergone [(99m)Tc]MIBI scan. All patients previously performed a (131)I-WBS with thyroglobulin (Tg) measurement and neck ultrasound or computerized tomography, or magnetic resonance imaging, or bone scan or positron emission tomography (PET) scan.


RESULTS
Patients were divided in two groups: group A (n=50) with known metastases and positive at a previous (131)I-WBS and group B (n=34) with known metastases, but negative at (131)I-WBS. All patients had elevated serum Tg level in absence of replacement therapy. Technetium-99m-MIBI scan showed 76.2% sensitivity in detecting metastases, Tg during opotherapy 64.3%, and the other imaging techniques combined 86.9%. Sensitivity of [(99m)Tc]MIBI was greater in metastases without (131)I uptake than in metastases with (131)I uptake, although the difference was not statistically significant.


CONCLUSIONS
Technetium-99m-MIBI scan improves sensitivity of Tg measurement in patients with suspected metastases from DTC during the course of opotherapy and is a useful alternative to fluorodeoxyglucose-PET or other imaging techniques in patients with elevated serum Tg and negative (131)I-WBS.
Ronga
G
G
Nuclear Medicine Unit, Department of Clinical Sciences, La Sapienza University of Rome, Rome, Italy. giuseppe.ronga@uniroma1.it
Ventroni
G
G
Montesano
T
T
Filesi
M
M
Ciancamerla
M
M
Di Nicola
A D
AD
Travascio
L
L
Vestri
A R
AR
Signore
A
A
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017256:Technetium Tc 99m Sestamibi; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary*
D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi