ESTRO 2023 - Abstract Book

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ESTRO 2023

Table 1

PO-1808 Dosimetry of α -emitting radioelements with TILDA-V in the context of targeted radionuclide therapy

A. Larouze 1 , M.E. Alcocer-Avila 2 , N. Esponda 3 , M.A. Quinto 3 , J.M. Monti 3 , C. Champion 1

1 Université de Bordeaux, Physique, Talence, France; 2 Université de Lyon, Physique, Villeurbanne, France; 3 Universidad de Rosario, Fisica, Rosario, Argentina Purpose or Objective Radiotherapy is nowadays one of the main methods for treating cancer, along with chemotherapy and surgery. In the current work, we focus on internal vectorized radiotherapy that consists in coupling a radionuclide to a biological molecule vector able to target tumor cells. Describing the properties of such a radio-element thus becomes challenging in medical physics research. This work aims to compare various α -emitters. Materials and Methods Through Monte Carlo numerical simulations, it may be possible to describe the radiation-induced energy deposits in biological samples. However, in order to correctly simulate transport in a given medium, Monte Carlo track structure codes require access to large databases of differential and total cross sections to describe the various interactions induced by the particles in the biological medium irradiated. In this context, we here detail all the models we developed and implemented into our TILDA-V code to describe the transport of helium particles in the biological medium. The dose deposit is then computed in a cell cluster consisting of 19 spherical cells of 7 µm radius and a centered nucleus of 5 µm radius. These calculations were carried out in three distributions of the radionuclide: intranuclear (N), intracytoplasmic (Cy), on the cell surface (CS). In all cases, the nucleus was taken as the target region. Results To check the reliability of the TILDA-V code, we provided comparisons with literature in terms of range, stopping power and dose profiles for α -particles. Calculated S-values are presented for various α -emitters as shown in Table 1 for 211At.