title: Assessment of glioma viability by estimating 201Tl SPET tumour uptake volume.
abstract: The aim of this study was to develop a quantitative method to assess viable tumour based on post-operative 201Tl single photon emission tomography (SPET). We studied 15 patients with histologically defined highly malignant gliomas in the post-operative phase before initiation of adjuvant treatment. A 201Tl index was calculated in two ways: maximal counts versus mean counts within a region of interest (ROI). The tumour uptake volume (TUV) within the lesion was calculated from the number of voxels that had 201Tl uptake above a threshold calculated from the uptake on the contralateral side. The threshold was set at three levels: A = 1.4 times the mean 201Tl uptake in a three-dimensional reference ROI + 96.7% confidence interval (the TUV was corrected by subtraction of the volume in the reference ROI that had uptake above the threshold with compensation for unequal ROI sizes); B = 1.4 times the mean reference ROI + 99% confidence interval; and C = maximum 201Tl uptake in the reference ROI. The SPET results were compared with the tumour volumes calculated from CT scans. Thirteen tumours showed high post-operative 201Tl uptake. The 201Tl index was not significantly correlated with histological grade within the group of highly malignant gliomas. 201Tl SPET tumour uptake volume method B was highly significantly correlated with CT estimated tumour volume. In conclusion, the measurement of post-operative 201Tl SPET tumour uptake volume demonstrates metabolically active glioma tissue and is an alternative method for the monitoring of glioma treatment response.
authors.affiliation: Department of Neurology, University Hospital, Lund, Sweden.
authors.forename: K
authors.initials: K
authors.lastname: Källén
authors.forename: B
authors.initials: B
authors.lastname: Geijer
authors.forename: A M
authors.initials: AM
authors.lastname: Andersson
authors.forename: S
authors.initials: S
authors.lastname: Holtås
authors.forename: E
authors.initials: E
authors.lastname: Ryding
authors.forename: I
authors.initials: I
authors.lastname: Rosén
mesh_terms: D000328:Adult; D000465:Algorithms; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery; D005260:Female; D005910:Glioma / Q000000981:diagnostic imaging* / Q000601:surgery; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D013794:Thallium Radioisotopes; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed
chemical_list: D013794:Thallium Radioisotopes