The retention indices of 201Tl-SPECT in brain tumors.
OBJECTIVE
The aim of this study was to assess the utility of 201Tl SPECT in the differential diagnosis of intracranial tumors and to determine the relationship between 201Tl uptake and histological types.


METHODS
Thirty-eight patients (19 males and 19 females) with thirty-eight brain tumors were evaluated with 201Tl-SPECT. The early and delayed 201Tl uptake ratio was calculated, and the retention index (RI) was applied as follows; RI = delayed uptake ratio/early uptake ratio.


RESULTS
The RI of malignant tumors was higher (0.72 +/- 0.18) than that of benign tumors (0.50 +/- 0.16) and the difference was statistically significant (p = 0.00045). The difference between high-grade glioma (0.80 +/- 0.15) and metastatic tumors (0.64 +/- 0.19) was statistically significant (p = 0.039).


CONCLUSIONS
201Tl-SPECT may add useful biochemical information and could differentiate malignant brain tumors from benign lesions, but the RI of metastatic tumors varied depending on the organs with the primary lesion and histological types.
Otsuka
Hideki
H
Department of Radiology, Ehime Central Prefectural Hospital, Japan. hotsuka@clin.med.tokushima-u.ac.jp
Shinbata
Hiroyuki
H
Hieda
Masashi
M
Yamashita
Kyo
K
Kitamura
Hiroki
H
Senba
Takatoshi
T
Kashihara
Kenichi
K
Tagashira
Hiroshi
H
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000145:classification* / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000378:metabolism; D002648:Child; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D013793:Thallium / Q000493:pharmacokinetics; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
D019275:Radiopharmaceuticals; C027549:thallium chloride; D013793:Thallium