title: [The most suitable parameter to distinguish brain tumor using 201Tl-chloride and SPECT].
abstract: We performed 201Tl single photon emission CT (SPECT) studies on 62 patients with brain tumors prior to any therapy for the tumor. Ten lesions of open-scar and 17 patients without brain tumor were also studied. The SPECT imaging were initiated 5 min (early image) and 4 hours (delayed image) after injection with 74 MBq of 201Tl-chloride. For a semi-quantitative analysis, we used the ratio of delayed count density to the early count density of the tumor (Td/Te), the ratio of tumor to normal brain tissue (Te/B(e)) on the early SPECT and the index of T/B ((Td/Te)/(Bd/B(e))). Delay to early ratio of 34 normal brain tissue (Bd/B(e)) was 1.22 +/- 0.15 and tended to decrease with the age. The Td/Te ratio of meningioma and region of operation scar was about 0.75 which was less than that of normal brain tissue. In 31 patients with astrocytic tumor, Td/Te ratio was clearly higher in poorly differentiated tumor than in well differentiated one. The index of Td/Te ratio was superior to Te/B(e) or T/B ratio for differentiating brain tumor and grading astrocytic tumor.
authors.affiliation: Department of Radiology, Yamagata University School of Medicine.
authors.forename: A
authors.initials: A
authors.lastname: Komatani
authors.forename: T
authors.initials: T
authors.lastname: Akutsu
authors.forename: K
authors.initials: K
authors.lastname: Yamaguchi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001254:Astrocytoma / Q000000981:diagnostic imaging / Q000473:pathology; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D002648:Child; D006801:Humans; D008875:Middle Aged; D013793:Thallium; D013794:Thallium Radioisotopes; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods
chemical_list: D013794:Thallium Radioisotopes; C027549:thallium chloride; D013793:Thallium