| Gliomas are the most common primary tumors of the central nervous system and represent about one - third of all intracranial tumors in adults. Astroglial neoplasms account for the vast majority of gliomas, and can be further divided into low - grade astrocytomas ( grade I and II lesions) and high - grade or malignant gliomas which include ana-plastic astrocytomas (grade III ) and glioblastoma multiforme ( grade IV )?In patients with expanding brain lesions, computed tomography (CT) and magnetic resonance imaging(MRI) provide non-specific information, even after contrast or gadolinium infusion. A contrast -enhancing tumor may be a malignant glioma, a cerebral abscess, a metastatic tumor or other lesions. Furthermore, CT and/or MRI may be unable to differentiate low - grade from high - grade gliomas, and cannot differentiate treatment - induced necrosis from recurrent tumor. Although histopathological examination is always a gold standard to assess the malignancy of tumors, it is clinically confined owing to its aggression , dangerousness and heterogeneity of glioma. So it is very difficult to obtain the accurate histopathological result before operation. Therefore it is important to develop new techniques that allow more precise diagnosis or prognosis of a brain mass. Functional imaging with position emission tomography ( PET) has been used to assesstumor viability and necrosis, and has bee proved effective in differentiating malignancy of low - grade from high - grade gliomas and recurrent tumor from radiation -induced change. However, the technology is available only in a limited number of institutions and is often cost -prohibitive. Thallium - 201 (201 TI) brain single - photon emission tomography (SPECT) is known to have a high sensitivity for detecting viable tumor, but its specificity is low due to the poor dedinition of images obtained with 1TI. In order to improve the quality of scinti-graphic images, a search for a new technetium - labelled agent was undertaken. 99mTc - sestamibi(99mTc - MIBI) ,an alterative radiophar-maceutical for myocardial perfusion studies, has also been proposed for use as an imaging agent for various tumors, including breast cancer, lung cancer and primary brain tumors. The difference between 99mTc - MIBI and 201TI in terms of sensitivity could be explained by the fact that 99mTc - MIBI images are superior in quality to 201TI images owing to physical properties of 99mTc. In order to clarify the prognostic value and diagnostic usefulness of 99mTc - MIBI brain SPECT for the i-dentification of low - grade form high - grade gliomas, and to evaluate the correlation between 99mTc - MIBI uptake and malignancy of gliomas ( histopathological grades) , we undertook the retrospective study.Materials and methodsCT or/and MRI and 99mTc - MIBI SPECT were carried out in all 33 adult patients with supratentorial brain lesions before operation. 15 with high - grade glioma ( high - grade glioma group) , 16 with low -grade glioma (low -grade glioma group) and other 2 patients with a variety of lesions including a cerebral abscess and a radiation - in-duced necrosis (different lesion group) were proven by histopathologi-cal examination after operation. The brain histopatholigical classification method ( 1993 ) of the World Health Organization was used. SPECT was performed 15 min after administration of 740 MBq 99mTc -MIBI and transverse, sagittal and coronal views were reconstructed. Using CT or/and MRI guidance, the region of interest (ROI) in lesion and ROI in its contralateral homologous mirror image were drawn on a transverse slice and the a 99mTc - MIBI uptake index was obtained as the ratio of average or maximum counts in the lesion ROI to average ormaximum counts in its contralateral homologous ROI, which was further compared respectively by means of 3 methods by one- side impair Student's t test.ResultsIn high - grade glioma group, 99mTc - MIBI index values ranged from 1. 9 to 6. 6(mean 3.76 ± 1.49) ; whereas they range from 0. 8 to 1. 7 ( mean 1. 27 ±...
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