title: Calculation of Nuclear Particles Production at High-Energy Photon Beams from a Linac Operating at 6, 10 and 15 MV.
abstract: Production of photonuclear particles in a tissue-equivalent medium has been calculated for linacs at 6, 10 and 15 MV from Varian TrueBeam. Based on the knowledge of bremsstrahlung fluence spectra and linac photon beam parameters, numerical integration was performed on the cross sections for photoparticle production of the constituent elements of tissue (2H,12C,13C,16O,17O,18O,14N,15N). At 15 MV, at the depth of photon maximum dose, the total absorbed dose due to neutrons, protons, alphas and residual nuclei from photon reactions in tissue (5.5E-05 Gy per Gy of photons) is comparable to that due to neutrons from accelerator head. Results reasonably agree with data reported in the literature using Monte Carlo models simulating linac head components. This work suggests a simple method to estimate the dose contributed by the photon-induced nuclear particles for high-energy photon beams produced by linacs in use, as it might be relevant for late stochastic effects.
authors: Department of Physics, University of Milan, Milan I-20133, Italy.
authors: Renato
authors: R
authors: Marchesini
authors: Department of Physics, University of Milan, Milan I-20133, Italy.
authors: Daniela
authors: D
authors: Bettega
authors: Department of Physics, University of Milan, Milan I-20133, Italy.
authors: Paola
authors: P
authors: Calzolari
authors: Fondazione IRCCS Istituto Nazionale dei Tumori, Milan I-20133, Italy.
authors: Emanuele
authors: E
authors: Pignoli
mesh_terms: D009010:Monte Carlo Method; D009502:Neutrons; D010315:Particle Accelerators; D017785:Photons; D011522:Protons; D011879:Radiotherapy Dosage
chemical_list: D011522:Protons