title: AAPM TG-43U1 formalism adaptation and monte carlo dosimetry simulations of multiple-radionuclide brachytherapy sources.
abstract: 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 103Pd and 125I was chosen. This combination promotes a higher dose rate than InterSource125 (loaded with 125I) and deeper tissue penetration than InterSource103 (loaded with 103Pd) while reducing the dose at long distance (beyond 2.5 cm) relative to InterSource125. 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.
authors.affiliation: Laboratoire d'Analyses par Réactions Nucléaires, University of Namur (FUNDP), Physics Department, LARN Lab, Rue de Bruxelles, 61, B-5000 Namur, Belgium. vincent.nuttens@fundp.ac.be
authors.forename: V E
authors.initials: VE
authors.lastname: Nuttens
authors.forename: S
authors.initials: S
authors.lastname: Lucas
mesh_terms: D001822:Body Burden; D001918:Brachytherapy / Q000379:methods* / Q000592:standards*; D003198:Computer Simulation; D006801:Humans; D007457:Iodine Radioisotopes / Q000032:analysis / Q000627:therapeutic use*; D008954:Models, Biological; D009010:Monte Carlo Method; D010165:Palladium / Q000032:analysis / Q000627:therapeutic use*; D017410:Practice Guidelines as Topic; D011868:Radioisotopes / Q000032:analysis / Q000627:therapeutic use; D011874:Radiometry / Q000379:methods*; D019275:Radiopharmaceuticals / Q000032:analysis / Q000627:therapeutic use; D011879:Radiotherapy Dosage; D012062:Relative Biological Effectiveness; D014481:United States
chemical_list: D007457:Iodine Radioisotopes; D011868:Radioisotopes; D019275:Radiopharmaceuticals; D010165:Palladium