Effects of corticosteroid inhalation therapy on the deposition pattern of Tc-99m human serum albumin radioaerosols in asthma.

This study evaluated the effects of steroid inhalation on the deposition pattern of Tc-99m human serum albumin (Tc-99m HSA) radioaerosols in 25 asthma patients. A total of 12 normal controls also underwent the same examination. The pattern of radioaerosol deposition was quantitatively evaluated as the percentage of total deposition (PTD) in the central, intermediate, and peripheral regions of the right lung. The baseline PTD was calculated before and after the administration of a 1-week course of inhalation therapy of 0.05 mg beclomethasone dipropionate four times daily. There were significant differences in PTD between normal controls and asthma patients. Significant differences were also found before and after corticosteroid inhalation therapy in asthma patients. In conclusion, a week-long course of beclomethasone dipropionate inhalation therapy does influence the deposition patterns of aerosols in asthma patients, based on the findings of Tc-99m HSA radioaerosol inhalation lung scintigraphy.