201Tl SPECT and 99mTc MIBI SPECT: A Comparative Study with Pathologic Grading of Meningioma

Choi, Gwang Shik; Kim, Oh Lyong; Bae, Jang Ho; Kim, Seong Ho; Choi, Byung Yon; Cho, Soo Ho

Abstract

Early and delayed 201Tl SPECT studies were performed on 20 patients with intracranial meningioma who were classified into 4 groups according to Helsinki Grading System: Grade I: benign(n=15), Grade II: atypical(n=5), Grade III: anaplastic(n=0) and Grade IV: sarcomatous(n=0). The early uptake indices(eTl, ratios of average counts/pixel in the lesion to those of contralateral area on early image) were relatively high in all types: Grade I, 3.05+/-1.44(mean+/-standard deviation): Grade II, 2.66+/-1.29. There was no statistical difference in relation to pathological grade. The delay uptake indices were 2.64+/-1.34 and 2.67+/-1.31 respectively, there was no statistical difference in relation to pathological grade. The retention indices(RI, ratios of delay to early uptake indices) were 0.92+/-0.35, 1.04+/-0.36 respectively. there was no statistical differences in relation to pathological grade. In ten cases presenting mitosis, RI was 1.11+/-0.30. But other cases not presenting mitosis RI was 0.80+/-0.34. There was significant difference between two groups p<0.05. The 99mTc-MIBI SPECT study was performed in 14 patients who classified into 4 group: Grade I(n=10) and Grade II(n=4). The uptake ratios were high in all types: Grade I, 6.70+/-3.63 and Grade II, 5.40+/-0.92. There were no statistical difference. In this study, there was no malignant case(Grade III, IV). In summary, if the further study including malignant cases, this study would aid in overcoming to overcome the limitation of CT, MRI about tumor differentiation, with regards to possible detection of presence of residual tumor and viability of tumor after treatment.