Quantitative SPECT for indium-111-labeled antibodies in the livers of beagle dogs.
Results are presented for SPECT computations of liver volumes and 111In-labeled antibody activities in the livers of eight normal beagle dogs. Administered activities ranged from 1 to 2 mCi. SPECT studies were acquired 1 day postinjection using a rotating gamma camera system with elliptical orbits in a 360-degree rotation (128 views, 15 sec/view, 64 x 64 matrices). Uniformity-corrected images were reconstructed by use of the circular harmonic transform algorithm with computer software developed in-house. Liver volumes and activities were computed from transverse slices, 1 pixel (6.25 mm) in thickness. Comparison of SPECT and autopsy data demonstrated that absolute values of percent differences between measured and computed liver volumes ranged from 1.0% to 7.2%. Absolute values of percent differences between autopsy data and computed 111In activities in the liver ranged from 2.3% to 7.5%. These results suggest that quantitative SPECT has the potential of becoming an important tool in clinical trials for determining activities and localization volumes of radiolabeled antibodies directly from radionuclide images.
Leichner
P K
PK
Radiation Oncology, Johns Hopkins Oncology Center, Baltimore, Maryland 21231.
Vriesendorp
H M
HM
Hawkins
W G
WG
Quadri
S M
SM
Yang
N C
NC
Stinson
R L
RL
Loudenslager
D M
DM
Frankel
T L
TL
Chen
X Y
XY
Klein
J L
JL
D000818:Animals; D000906:Antibodies; D004285:Dogs; D007205:Indium Radioisotopes; D008099:Liver / Q000000981:diagnostic imaging*; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
D000906:Antibodies; D007205:Indium Radioisotopes