Scintigraphy for interpretation of malignant tumours of the head and neck: comparison of technetium-99m-hexakis-2-methoxyisobutylisonitrile (Tc-MIBI) and thallium-201-chloride (Tl-201).
OBJECTIVE
The purpose of this study was to compare the usefulness of technetium-99m-hexakis-2-methoxyisobutylisonitrile (99Tc(m)-MIBI) and thallium-201-chloride (Tl-201) as scintigraphic agents.


METHODS
Dynamic and static scintigraphic imaging with 99Tc(m)-MIBI and Tl-201 were performed on patients with a variety of malignant and benign tumours. Factors of the grade of the static scan, the blood flow index, the early and delayed retention indexes, and the tumour retention index were obtained from the scintigraphy. In addition to these factors, the grade of tissue differentiation and tumour size were evaluated to clarify the difference between 99Tc(m)-MIBI and Tl-201 for the diagnosis of malignant tumours of the head and neck.


RESULTS
99Tc(m)-MIBI accumulation depended upon the blood flow index in the early static scan, but this accumulation did not correlate with tumour size. The accumulation in most subjects decreased in the delayed static scan, and the tumour retention index had a tendency to decrease with the grade of tissue differentiation. Tl-201 accumulation depended upon the blood flow index in the early static scan similar to 99Tc(m)-MIBI, and the accumulation correlated with tumour size, unlike 99Tc(m)-MIBI. The tumour retention index had a tendency to increase with the grade of tissue differentiation. Thus, the tumour retention indexes showed opposite behaviours between 99Tc(m)-MIBI and Tl-201, but they both accurately determined tumour malignancy.


CONCLUSIONS
There was no major difference between 99Tc(m)-MIBI and Tl-201scintigraphy with respect to accuracy of diagnosis of malignant tumours of the head and neck. However, 99Tc(m)-MIBI was superior to Tl-201 for small-size tumours and Tl-201 was useful for large-size tumours.
Sato
T
T
Department of Oncology, Maxillofacial Radiology Division, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8544, Japan. sato@denta.hal.kagoshima-u.ac.jp
Kawabata
Y
Y
Kobayashi
Y
Y
Suenaga
S
S
Indo
H
H
Kawano
K
K
Iwashita
Y
Y
Morita
Y
Y
Majima
H J
HJ
D000230:Adenocarcinoma / Q000000981:diagnostic imaging; D000235:Adenolymphoma / Q000000981:diagnostic imaging; D008949:Adenoma, Pleomorphic / Q000000981:diagnostic imaging; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D002454:Cell Differentiation; D005260:Female; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D012039:Regional Blood Flow / Q000502:physiology; D012189:Retrospective Studies; D017256:Technetium Tc 99m Sestamibi / Q000493:pharmacokinetics; D013793:Thallium; D013794:Thallium Radioisotopes / Q000493:pharmacokinetics; D013997:Time Factors
D019275:Radiopharmaceuticals; D013794:Thallium Radioisotopes; C027549:thallium chloride; D017256:Technetium Tc 99m Sestamibi; D013793:Thallium