Estimating residence times and their associated errors in patient absorbed-dose calculation.
OBJECTIVE
An approach for estimating organ residence times (tau) and their errors in patient internal emitter radiation dosage calculations has been determined.


METHODS
Using a modeling algorithm and its associated parameters, chimeric anti-CEA monoclonal antibody (cT84.66) patient organ uptake data and residence times of source organ activity were calculated. Through the covariance matrix of the model's parameters and subsequent Monte Carlo simulations, errors in organ residence time (gamma tau) also were estimated


RESULTS
These relative tau errors were found to be model-dependent; increasing as the number of organs being simultaneously modeled in a set of two patients being considered for 90Y-cT84.66 radioimmunotherapy.


CONCLUSIONS
Use of modeling and Monte Carlo methods provide a general, direct procedure for calculating the degree of accuracy of activity integrals and other mathematical functions of kinetic variables.
Kaplan
D D
DD
Division of Radiology, City of Hope National Medical Center, Duarte, California 91010, USA.
Williams
L E
LE
Clarke
K G
KG
Odom-Maryon
T L
TL
Liu
A
A
Lopatin
G
G
Raubitschek
A A
AA
Wong
J Y
JY
D000465:Algorithms; D006801:Humans; D007205:Indium Radioisotopes / Q000627:therapeutic use; D009010:Monte Carlo Method; D016499:Radioimmunotherapy; D011879:Radiotherapy Dosage; D015021:Yttrium Radioisotopes / Q000627:therapeutic use
D007205:Indium Radioisotopes; D015021:Yttrium Radioisotopes