Dose Point Kernel calculation and modelling with nuclear medicine dosimetry purposes

I. SCARINCI; M. VALENTE; P. PÉREZ

Montevideo

Simposio; X Latin American Symposium on Nuclear Physics and Applications; 2013

Monoclonal labeled antibodies administration with radioimmunotherapy purposes in nuclear medicine procedures is performed by depositing specific radiactivity concentrations on tumoral regions with the aim of hurt tumoral tissue. Kinetic characteristics of this antibodies produce a non-uniform activity distribution over the patient body and, in most of cases with dosimetric purposes, it is assumed uniformly to simplify quantification on internal dosimetry. Finally, its produce a decrease on the dosimetry calculation presicion involved on an oncologic treatment.Treatment planification requires an estimation of the radionuclide's delivered dose distribution that can be approximated by numeric or analytic methods [2]. Numerically, it can be estimated through Monte Carlo methods; while analitically, it can be calculated by an activity distribution convolution using Dose Point Kernels.Actually, almost all of the used calculations in treatment planifications in clinical situations are performed by a simplification of the Boltzmann radiation transport equation, taking into account infinite homogeneous media and using the linearity principle. Monte Carlo method provides, other hand, the calculation capacity and presicion that can not be achieved by analytic approximations. Actual technologic advances allow high data processing and calculus capacity, so Monte Carlo simulations result in an important tool for the radiation transport study over soft tissues.This work is focused on the utilization of the Monte Carlo method with the aim of performing Dose Point Kernels calculations over complex systems that involve biologic media in finite dimensions. This precisely results will be used to perform an hybrid dose delivery calculation considering a real activity distribution as a non-homogeneous kernels distribution, in a patient-specific media distribution[5], for its addition to a novel calculation system developed with nuclear medicine dosimetry purposes.