title: Visual and semi-quantitative assessment of brain tumors using (201)Tl-SPECT.
abstract: OBJECTIVE
  To evaluate the usefulness of (201)Tl-SPECT in differentiating benign from malignant brain tumors.
  
  
  METHODS
  Eighty-eight patients (44 males and 44 females) with 58 high-grade (WHO grade III-IV) and 30 low-grade (WHO grade I-II) tumors were evaluated with (201)Tl-SPECT. (1) Visual assessment was performed by board-certificated radiologists using (201)Tl-SPECT. Tumors were classified in two groups (Tl-positive and Tl-negative) and scored using the five grade evaluation system. Receiver operating characteristic (ROC) analysis was performed in the Tl-positive group. (2) Semi-quantitative assessment involved measurement of early and delayed (201)Tl uptake, and the retention index (RI) was applied as follows: RI=delayed uptake ratio/early uptake ratio. Three combinations of RI using mean and maximum values of the region of interest were calculated.
  
  
  RESULTS
  (1) Seventy-four Tl-positive and 14 Tl-negative tumors. The area under the ROC curve (AUC) estimated by three radiologists exceeded a value of 0.7. The value was greater when estimated by the more experienced radiologist. (2) In all RIs, the difference of RI between high-grade tumors and low-grade tumors was statistically significant.
  
  
  CONCLUSIONS
  A visual and semi-quantitative assessment using (201)Tl-SPECT was found to be useful for differentiating benign from malignant brain tumors.
authors.affiliation: Department of Radiology, Tokushima University Hospital, Tokushima, Japan.
authors.forename: Ayumi
authors.initials: A
authors.lastname: Nose
authors.forename: Hideki
authors.initials: H
authors.lastname: Otsuka
authors.forename: Hayato
authors.initials: H
authors.lastname: Nose
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Otomi
authors.forename: Kaori
authors.initials: K
authors.lastname: Terazawa
authors.forename: Masafumi
authors.initials: M
authors.lastname: Harada
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000000981:diagnostic imaging*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012189:Retrospective Studies; D013794:Thallium Radioisotopes; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
chemical_list: D013794:Thallium Radioisotopes