Hadadi, Asghar

Department of Medical Radiation Engineering Science and Research Branch, Islamic Azad University, Tehran, Iran

[ 1 ] - Unexpected dose and the biological effect of neutron contamination in linear accelerators

Employing High-energy photons in medical linear accelerators can lead to neutron contamination. The relative biological effect of neutrons is 20 times higher than photons. Consequently, its damage to the biological tissue is much higher and unobtrusive. In this study, we calculated neutron equivalent dose in a medical linear accelerator by the FLUKA Monte Carlo code system. The results show tha...

[ 2 ] - The influence of neutron contamination on pacemaker in photon beam radiotherapy by LINAC using the Monte Carlo method

  In radiation therapy with high-energy photon beams (E > 10 MV) neutrons are generated mainly in LINACs head thorough (γ,n) interactions. These neutrons affect the shielding requirements in radiation therapy rooms. According to the AAPMTG-34 report, photon absorbed dose of 10Gy can cause permanent damage to the pacemaker and the dose of 2Gy can make minor changes in the functioning of the pac...

[ 3 ] - Using Zirconium Borohydride as Neutron Shield in LINAC head

Introduction: One of the concerns about using of high energy photons in radiotherapy is neutron contamination production. The threshold energy of photoneutron production in most materials with high atomic number is about 7MeV. Therefore, it seems to be logical that the main components with high atomic number elements used in the LINAC head have a large contribution to the neutr...

[ 4 ] - Neutron Contamination Unexpected Dose in Varian LINAC

Introduction: Neutron contamination is very harmful for the patients receiving radiation therapy due to the high relative biological effect of neutrons. Medical linear accelerators head are made up of materials with high atomic numbers, and High-energy photons interaction with heavy materials can produce neutron contamination. In this study, neutron equivalent dose, neutron spe...

[ 5 ] - The influence of neutron contamination on pacemaker in photon beam radiotherapy by LINAC using the Monte Carlo method

Introduction: In radiation therapy with high-energy photon beams (E > 7 MeV) neutrons are generated mainly in LINACs head thorough (γ, n) interactions. These neutrons affect the shielding requirements in radiation therapy rooms. According to the protocol TG-34, photon absorbed dose of 10Gy can cause permanent damage to the pacemaker and the dose of 2Gy can make minor changes in...

[ 6 ] - Optimization of a SPECT system for imaging of 90Y in liver using Monte Carlo method

Introduction: Acquiring a high quality image has assigned an important concern for obtaining accurate diagnosis in nuclear medicine. Detector and collimator are critical component of Single Photon Emission Computed Tomography (SPECT) imaging system for giving accurate information from exact pattern of radionuclide distribution in the target organ. The images are strongly affect...

[ 7 ] - Investigation of LINAC Structural Effects on Photoneutron Specified Parameters Using FLUKA code

Introduction: The utilization of high-energy photons in the medical linear accelerator can lead to photoneutron production. This study aimed to evaluate the effect of the physical components of the head, including flattening filter (FF) andmultileaf collimator (MLC), as well as the dependence of therapeutic field size on the photoneutron spectrum, dose, and flux. <str...