99mTc-ENS ventilation scintigraphy: preliminary study in human volunteers

Exogenous natural surfactant (ENS) labeled with (99m)Tc ((99m)Tc-ENS, 900-1110 MBq), a new radiopharmaceutical for ventilation scintigraphy, was nebulized during 3 min to five volunteers. For comparative purposes, (99m)Tc-diethylenetriamine pentaacetic acid (DTPA) was studied in the same way. (99m)Tc-ENS images were of at least the same quality as (99m)Tc-DTPA images. However, in smoking volunteers, the (99m)Tc-DTPA images show some areas that seemed to be not well-ventilated, although these areas appeared well-ventilated when the study was performed with (99m)Tc-ENS. These results suggest that (99m)Tc-ENS can be used for ventilation scintigraphy to allow the observation of some areas that cannot been visualized using (99m)Tc-DTPA as ventilation agent.