This paper presents a preliminary study on multiple-radionuclide sources for brachytherapy. An adaptation of the AAPM TG-43U1 formalism is proposed in order to derive the dosimetry parameters of multiple-radionuclide sources from mono-radionuclides. The adapted formalism is applied to a bi-radionuclide case with the help of Monte Carlo calculations (MCNPX 2.5.0). InterSource™ seed loaded with Pd and I was chosen. This combination promotes a higher dose rate than InterSource (loaded with I) and deeper tissue penetration than InterSource (loaded with Pd) while reducing the dose at long distance (beyond 2.5 cm) relative to InterSource. In conclusion, this work shows the benefits of combining different radionuclides inside the same seed and proposes an adaptation of the AAPM TG-43U1 formalism for the implementation of multiple-radionuclide sources in current treatment planning systems.
Technological Platform Synthesis, Irradiation and Analysis of Materials
Facility/equipment: Technological Platform