PMID- 18844481
OWN - NLM
STAT- MEDLINE
DCOM- 20090512
LR  - 20151119
IS  - 1941-2711 (Print)
IS  - 1941-2711 (Linking)
VI  - 22
IP  - 1
DP  - 2009 Mar
TI  - Corrections in dose assessment of 99mTc radiolabeled aerosol particles targeted 
      to central human airways using planar gamma camera imaging.
PG  - 45-54
LID - 10.1089/jamp.2007.0664 [doi]
AB  - The dose of inhaled radiolabeled aerosols is usually assessed using gamma (GC) 
      camera imaging. Because of the complex and inhomogeneous structure of the lung, 
      consisting of soft tissue, the thoracic skeleton, blood vessels, and air spaces, 
      proper attenuation correction coefficients are difficult to evaluate and the 
      estimated doses bear high uncertainty. One hundred milliliters of aerosol boli 
      composed of 100 nm diameter (99m)Tc radiolabeled carbon particles (Technegas) 
      were targeted either to the airways (AW) or to 800-mL volumetric lung depth 
      (alveoli, AL) in 11 healthy volunteers. In addition, 750-mL full breaths (FB) of 
      aerosol were inhaled to a 800-mL lung depth. The deposited dose was measured by 
      collecting aerosol from inhaled and exhaled air stream on filters, which were 
      analyzed for radioactivity. Lung imaging was performed using a planar GC 
      (posterior). Ratios of GC counts to deposited dose (GC/DD) were similar after FB 
      and AL administration, but twofold lower after AW administration (p < 0.01). 
      Associated attenuation correction factors (ACF) were 2.5 +/- 0.5 (FB), 2.2 +/- 
      0.4 (AL), and 5.5 +/- 1.6 (AW, p < 0.01). Both GC/DD and ACF were highly 
      correlated to the aerosol distribution index (central to peripheral ratio, C/P). 
      After shallow bolus administration there was a negative correlation between body 
      mass index and GC/DD. Inhalation of radioaerosols used in medical diagnosis and 
      therapy in combination with high central airway deposition results in an 
      underestimation of the deposited dose based on planar GC imaging. The aerosol 
      distribution index C/P may provide one suitable indicator for corrections, which 
      should be confirmed in future studies by individual attenuation analysis based on 
      radiotracer transmission measurements.
FAU - Moller, Winfried
AU  - Moller W
AD  - Helmholtz Zentrum Munchen-German Research Center for Environmental Health, 
      Clinical Cooperation Group Inflammatory Lung Diseases, Gauting and Neuherberg, 
      Germany. moeller@helmholtz-muenchen.de
FAU - Felten, Kathrin
AU  - Felten K
FAU - Meyer, Gabriele
AU  - Meyer G
FAU - Meyer, Peter
AU  - Meyer P
FAU - Seitz, Jurgen
AU  - Seitz J
FAU - Kreyling, Wolfgang G
AU  - Kreyling WG
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Aerosol Med Pulm Drug Deliv
JT  - Journal of aerosol medicine and pulmonary drug delivery
JID - 101475057
RN  - 0 (Aerosols)
RN  - 7440-26-8 (Technetium)
MH  - Adult
MH  - Aerosols/administration & dosage/*metabolism
MH  - Aged
MH  - *Gamma Cameras
MH  - Humans
MH  - Lung/*metabolism
MH  - Middle Aged
MH  - *Technetium
MH  - Tissue Distribution
EDAT- 2008/10/11 09:00
MHDA- 2009/05/13 09:00
CRDT- 2008/10/11 09:00
PHST- 2008/10/11 09:00 [pubmed]
PHST- 2009/05/13 09:00 [medline]
PHST- 2008/10/11 09:00 [entrez]
AID - 10.1089/jamp.2007.0664 [doi]
PST - ppublish
SO  - J Aerosol Med Pulm Drug Deliv. 2009 Mar;22(1):45-54. doi: 10.1089/jamp.2007.0664.