Direct comparison of thallium-201 and technetium-99m MIBI SPECT of a glioma by receiver operating characteristic analysis

The diagnostic value of single photon-emission computed tomography (SPECT) has been assessed using arbitrarily determined sensitivity and specificity cut-off values. The diagnostic accuracy of thallium-201 (Tl-201) SPECT and technetium-99m methoxyisobutylisonitrile (Tc-MIBI) SPECT were compared for patients with primary glioma using receiver operating characteristic (ROC) analysis. The study population included 59 patients with gliomas. Tl and Tc-MIBI SPECT images were obtained using a multi-detector SPECT machine 15 min (early) and 3 hours (delayed) after intravenous injection of 74 MBq of Tl-chloride or 740 MBq of Tc-MIBI. The regions of interest were set on the tumor and contralateral normal white matter and tumor : normal ratios were calculated. The area z-score (Az) values were calculated from the areas under the ROC curves. All Az values were high and no statistical difference was observed between the two modalities. Both Tl and Tc-MIBI SPECT are useful imaging modalities for the evaluation of glioma malignancy.