RT Journal Article
SR Electronic
T1 Evaluation of Pulmonary Perfusion Using an Endothelial Cell Tracer in Supine Humans and Dogs
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 1726
OP 1726
VO 57
IS supplement 2
A1 Levac, Xavier
A1 Harel, François
A1 Vincent, Finnerty
A1 Nguyen, Quang
A1 Letourneau, Myriam
A1 Marcil, Sophie
A1 Fournier, Alain
A1 Dupuis, Jocelyn
YR 2016
UL http://jnm.snmjournals.org/content/57/supplement_2/1726.abstract
AB 1726Objectives Pulmonary perfusion is not homogeneously distributed and its variations could be of diagnostic value. PulmoBind is a ligand of the adrenomedullin receptor expressed in endothelial cells of lung capillaries. The spatial distribution of lung perfusion has never been evaluated using a molecular tracer.Methods We studied subjects enrolled into the PulmoBind phase I safety study (Clinicaltrials.gov: NCT01539889). Healthy humans (n=19) were injected with 5 mCi to 15 mCi 99mTc-PulmoBind for SPECT imaging. Results were compared with 99mTc-PulmoBind in quadruped mammals (dogs, n=5). Imaging was performed in the supine position and activity was determined as a function of cumulative voxels along different planes.The right and left lungs were included into one ROI for each axis. For the mediolateral axis, the right lung was flipped and translated to align geometrically with the left lung and included into one ROI.Results Mean radiochemical purity of PulmoBind was 95 ± 4% (mean±SD). Peak PulmoBind uptake in humans was 58%±1% (mean±SEM) of the injected dose. Dorsal activity was 18.1%±2.1% greater than ventral, and caudal activity was 25.7%±1.6% greater than cranial. Lateral activity was only mildly higher than medial by 7.0%±1.0%. In supine dogs, similar but higher PulmoBind gradients were present: dorsal 28.6%±2.5%, caudal 34.1%±5.0% and lateral 18.1%±2.0%.Conclusions The perfused pulmonary circulation of supine humans, assessed by an adrenomedullin receptor ligand, is not homogeneously distributed with more prominent distribution in dorsal and caudal regions. It is similar to a supine quadruped mammal confirming the presence of a gravitational perfusion gradient detectable with this tracer. Future studies are needed to determine if this novel endothelial cell tracer could be used to detect physiologic and pathologic variations of lung perfusion. Supported by the Quebec Consortium for Drug Discovery (CQDM).