THE CANADIAN EXERCISE TECHNETIUM-99M-LABELED TEBOROXIME SINGLE-PHOTONEMISSION COMPUTED TOMOGRAPHIC STUDY

Background. (99)mTc-labeled teboroxime undergoes rapid washout from th e myocardium. For this reason, its use has been favored in conjunction with pharmacologic stress, which enables patient positioning before t racer administration, and multidetector single-photon emission compute d tomography (SPECT), which enables rapid acquisition. We evaluated tr eadmill exercise Tc-99m-labeled teboroxime SPECT with single-detector systems for the detection of coronary artery disease. Methods and Resu lts. Treadmill exercise Tc-99m-labeled teboroxime SPECT was compared w ith analogous (TI)-T-201-labeled imaging in 108 patients. Teboroxime w as injected first during exercise and then at rest. Nine myocardial se gments per study were scored with respect to uptake of activity during stress and at rest (teboroxime) or after redistribution ((TI)-T-201). Perfusion was defined as normal, reversible, or fixed. Overall agreem ent of (TI)-T-201 versus teboroxime segmental perfusion (normal vs abn ormal) was 772/961 (80.3%; chi 2 = 258; p < 0.01; kappa = 0.51) or (no rmal vs reversible vs fixed) 711/961 (74%; chi(2) = 296; p < 0.001; ka ppa = 0.42). Fifty-six patients also underwent selective coronary angi ography. Stenoses greater than 50% of lumenal diameter were drawn on i ndividualized coronary artery diagrams applied to polar plots of scint igraphic segments to compare detection of coronary artery diagrams app lied to polar plots of scintigraphic segments to compare detection of coronary artery disease. Sensitivity and accuracy of teboroxime were 0 .80 and 0.79, respectively, compared with 0.84 and 0.82 for (TI)-T-201 (difference not significant). Mean imaging procedure time was 113.6 m inutes for teboroxime and 240.5 minutes for (TI)-T-201 (p < 0.001). Co nclusion. Tc-99m-labeled teboroxime is amenable to simple modification s of routine treadmill exercise SPECT myocardial perfusion imaging pro tocols with widely available single-detector SPECT systems. This modal ity provides results similar to those of exercise (TI)-T-201 spect and is significantly faster.