Evaluation of 99Tcm-labelled α-D-glucose 1-phosphate aerosols for SPECT ventilation lung imaging

The purpose of the present investigation was to evaluate 99Tcm-labelled α-D-glucose 1-phosphate (GP) aerosols for single photon emission computed tomography (SPECT) ventilation lung imaging in comparison to 99Tcm-diethylenetriaminepentaacetate (DTPA) aerosols. Ten normal nonsmoking male volunteers were included in this study. 99Tcm-GP was placed in the nebulizer (Venticis II) and inhalation continued for 5 min of normal breathing with oxygen flowing through. In 10 subjects dynamic images were obtained from the posterior position for 90 min by the use of a gamma camera. Then images of the lung (anterior, posterior and laterals) were recorded. Decay corrected clearance curves and kep values were obtained by the pulmonary epithelial programme and T1/2 values were calculated. The same procedure was followed for 99Tcm-DTPA in the same subjects 2 weeks later. SPECT studies of the lung were performed in five subjects after inhalation of 99Tcm-GP aerosols. Clearance curves were monoexponential. The mean T1/2 values were 316.5 ± 44.7 and 80.8 ± 13.4 min for 99Tcm-GP and 99Tcm-DTPA, respectively. The difference was significant. On scintigraphic images, 99Tcm-GP showed high alveolar deposition and low adhesion to major airways like 99Tcm-DTPA. However, it is preferred to 99Tcm-DTPA for SPECT studies because of its prolonged pulmonary clearance. (Author)