Estimation of uncertainties on dose calculations of the 99mTc-MDP-injected patients in nuclear medicine.
The internal exposures of the patients in nuclear medicine can be calculated based on the equations and data in ICRP Publications 53 and 80. Physical and biological parameters are used for the calculation, and both include uncertainties. Physical parameters can be considered as more precise than biological parameters, so that uncertainties originated from biological parameters are more important. Absorbed fractions (AFs) have been calculated by Monte-Carlo method using medical internal radiation dose (MIRD)-type mathematical phantoms. They depend on the shapes and sizes of the phantoms used in simulations. For estimating shape- and size-related uncertainties, AFs of pairs of source regions and target tissues of the patient-injected 99mTc-MDP were calculated by using EGS4 codes and a voxel phantom of Japanese male. By simply resizing the voxels of the phantom, the dependencies of size for AFs were calculated, and the uncertainties caused by the cumulated activities in source regions were also estimated by assuming these parameters distributions as Gaussian.
Akahane
Keiichi
K
Radiological Protection Section, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Japan. akahane@nirs.go.jp
Nishizawa
Kanae
K
Iwai
Kazuo
K
Saito
Kimiaki
K
D001822:Body Burden; D003198:Computer Simulation; D003627:Data Interpretation, Statistical; D007275:Injections, Intravenous / Q000706:statistics & numerical data; D008954:Models, Biological; D009683:Nuclear Medicine / Q000706:statistics & numerical data*; D019275:Radiopharmaceuticals / Q000008:administration & dosage / Q000493:pharmacokinetics; D012062:Relative Biological Effectiveness; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013669:Technetium Tc 99m Medronate / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D014915:Whole-Body Counting / Q000379:methods*
D019275:Radiopharmaceuticals; D013669:Technetium Tc 99m Medronate