SU‐E‐T‐13: Radiobiological Model for Evaluation of Targeted Radionuclide Therapeutic Potential in Metastases Control

Abstract

Purpose: To provide a rabiobiological evaluation tool based on a mathematical model for control of metastases during treatment with the use of FDG beta emissions as therapeutic agent. Methods: Analytical and numerical solution of a nonlinear set of equations in order to describe the interaction between beta radiation and clonogenic transformed cells which are part of a primary tumor and related metastases. Under the consideration that beta emissions in this particular case can be taken as high LET radiation, the critical time and fraction number for local minima in the transformed cell population and can be found in closed form. Results: This theory can explain the observed behavior for the primary tumor and particularly for metastases in a mice‐melanoma experimental model, where 3 out of 7 of the treated animals showed no metastases. This result suggests the possibility of a fractionation scheme for total dose which can produce the same effect when repeated intravenous inoculations are provided at the proper critical time intervals. Conclusions: For metastases control with radionuclides, which are beta emitters like FDG as therapeutic agents, a treatment planning and follow up is possible from a quantitative point of view using a radiobiological kinetic model based on DNA damage mechanisms.Funding was provided by the School of Physics, Faculty of Science and Consejo de Desarrollo Científico y Humanístico, Universidad Central de Venezuela and Física Médica C. A.