EN
Gadolinium neutron capture therapy (GdNCT) is
used for treatment of radioresistant malignant tumors. The
absorbed dose in GdNCT can be divided into four primary
dose components: thermal neutron, fast neutron, photon
and natural gadolinium doses. The most significant
is the dose created by natural gadolinium. The amount of
gadolinium at the irradiated region is changeable and depends
on the gadolinium delivery agent and on the structure
of the location where the agent is injected. To de-
fine the time dependence of the gadolinium concentration
ρ(t) in the irradiated region the pharmacokinetics of
gadolinium delivery agent (Magnevist) was studied at intratumoral
injection in mice and intramuscular injection
in rats. A polynomial approximation was applied to the experimental
data and the influence of ρ(t) on the relative
change of the absorbed dose of gadolinium was studied.