Correlation of preoperative thallium SPECT with histological grading and overall survival in adult gliomas.
BACKGROUND
The management and prognosis of a glioma depend on the tumour's histological grade. Thus, preoperative prediction of the grade is routinely needed to indicate whether surgery or biopsies are required. It has been proposed that thallium single photon emission computed tomography (SPECT), in a relative short series, will aid this prediction.


OBJECTIVE
To confirm the correlation between the results of preoperative thallium SPECT and grade of tumour as well as patient survival, and to define the cut-off value of the optimal thallium index for the detection of high grade gliomas in a large series of patients.


METHODS
One hundred and eighteen patients treated for glioma were retrospectively included in this study. All patients underwent preoperative 201Tl SPECT upon initial presentation and were referred for neurosurgery. Initial scintigraphic findings were correlated with the histological grade of the tumour and overall patient survival.


RESULTS
Thallium uptake was highly correlated with histological grade; the mean thallium indices for low grade and high grade gliomas were 1.8 and 4.9, respectively. On the basis of receiver operating characteristic analysis, the optimal cut-off value of the thallium index for the detection of high grade glioma was determined. By using 2.2 as the value for the threshold thallium index, the sensitivity and specificity were 93% and 72%, respectively. Kaplan-Meier estimates of the overall survival curves, as a function of the thallium index, indicated that it was correlated with the overall survival (P<0.001).


CONCLUSIONS
Thallium SPECT provides useful information about the histological grade of the tumour and overall patient survival. Additionally, in spite of its relatively weak resolution, it appears to be a powerful routine clinical tool for the management of gliomas.
Comte
Frédéric
F
Service de Médecine Nucléaire, CHU Montpellier, France. f-comte@chu-montpellier.fr
Bauchet
Luc
L
Rigau
Valérie
V
Hauet
Jean Robert
JR
Fabbro
Michel
M
Coubes
Philippe
P
Chevalier
Jeanine
J
Mariano-Goulart
Denis
D
Rossi
Michel
M
Zanca
Michel
M
D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology* / Q000473:pathology; D005602:France / Q000453:epidemiology; D005910:Glioma / Q000000981:diagnostic imaging* / Q000453:epidemiology* / Q000473:pathology; D015994:Incidence; D011379:Prognosis; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D012680:Sensitivity and Specificity; D016019:Survival Analysis; D015996:Survival Rate; D013793:Thallium; D015899:Tomography, Emission-Computed, Single-Photon / Q000706:statistics & numerical data*
D019275:Radiopharmaceuticals; C027549:thallium chloride; D013793:Thallium