The APE nebuliser--a new delivery system for the alveolar targeting of particulate technetium 99m diethylene triamine penta-acetic acid.
We report the validation of a new delivery system--aerosol production equipment (known by the acronym APE), which generates a particulate aerosol of technetium 99m diethylene triamine penta-acetic acid (DTPA) with a mass-median aerodynamic diameter of 0.35 microns and a geometric standard deviation of 1.8 Twenty subjects were studied; in group 1 were 12 healthy men with normal spirometry; in group 2 were 8 men with AIDS who had mildly abnormal lung function following an episode of pneumocystis pneumonia-spirometry FEV1 3.08 (0.73) L, FVC 4.83 (0.82) L [mean (SD)]. The APE nebulizer was used to form a particulate aerosol with 200 MBq of 99mTc DTPA, which was collected in a 35 1 reservoir of air, which was subsequently inhaled. The mean (SD) inhalation time was 4.7 (0.44) min. The output of the nebulizer (% of activity inhaled) was 82%. Using planar imaging, the penetration index (right lung) in group 1 was 0.93 (0.18), mean (SD), and in group 2 it was 0.91 (0.12). There was virtually no tracheal deposition and extrapulmonary deposition (oropharynx and stomach) was less than 5% of the aerosol delivered. Single-photon emission tomography (SPET) studies carried out in five patients from group 1 confirmed homogeneous intrapulmonary deposition of 99mTc-DTPA. In view of the excellent intrapulmonary deposition of 99mTc-DTPA produced by the APE nebulizer, it may provide an alternative to conventional ventilation studies using radioactive gases.
Miller
R F
RF
Department of Medicine, University College and Middlesex School of Medicine, Middlesex Hospital, London, UK.
Jarritt
P H
PH
Lui
D
D
Kidery
J
J
Semple
S J
SJ
Ell
P J
PJ
D000163:Acquired Immunodeficiency Syndrome / Q000150:complications; D000328:Adult; D000336:Aerosols; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D008297:Male; D009330:Nebulizers and Vaporizers; D011020:Pneumonia, Pneumocystis / Q000150:complications / Q000000981:diagnostic imaging*; D011650:Pulmonary Alveoli / Q000000981:diagnostic imaging*; D016284:Technetium Tc 99m Pentetate / Q000008:administration & dosage; D015899:Tomography, Emission-Computed, Single-Photon; D014692:Ventilation-Perfusion Ratio; D014980:Xenon Radioisotopes
D000336:Aerosols; D014980:Xenon Radioisotopes; D016284:Technetium Tc 99m Pentetate