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...

background: one of the main causes of induction of secondary cancer in radiation therapy is neutron contamination received by patients during treatment. objective: in the present study the impact of wedge and block on neutron contamination production is investigated. the evaluations are conducted for a 15 mv siemens primus linear accelerator.  methods: simulations were performed using mcnpx mon...

Background: One of the main causes of induction of secondary cancer in radiation therapy is neutron contamination received by patients during treatment.Objective: In the present study the impact of wedge and block on neutron contamination production is investigated. The evaluations are conducted for a 15 MV Siemens Primus linear accelerator. Methods: Simulations were performed using MCNPX Monte...

Background: Neutron contamination is produced in electron beams of linac when tooth or dental materials are located in the path of beam. Objective: This study aims to determine the neutron dose contamination from different dental restoration materials in electron mode of a linac. Material and Methods: In this experimental study, the neutron dose contamination was calculated in the p...

Dose to the total body from induced radiation resulting from primary exposure to radiotherapeutic beams is not detailed in routine treatment planning though this information is potentially important for better estimates of health risks including secondary cancers. This information can also allow better management of patient treatment logistics, suggesting better timing, sequencing, and conduct ...

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...

9 The cross section for photoneutron production in Be at energies of 1. 692, 1. 720, and 1. 78 Mev has been investigated using radioisotope gamma-ray sources. Neutron counting was by manganous sulfate bath and a long counter. Gamma-ray counting was by a scintillation spectrometer consisting of a Nal(Tl) scintillation crystal and a 256-channel pulse^height analyzer. The following results were ob...

Some recent studies in Italy have focused on the possibility of exploiting clinical high energy electron linear accelerators, normally used in photon radiotherapy, as photo-neutrons source for in-hospital neutron medical applications. In-Hospital photo-neutron radiotherapy extends the possibilities of Boron Neutron Capture Therapy (BNCT) to external treatment of diffused tumors when other metho...

Neutron detection time distribution is an important factor for the dead-time correction for moderator type neutron detectors used in pulsed radiation fields. Measurements of the neutron detection time distributions of multisphere LiI detectors (2Ó, 3Ó, 5Ó, 8Ó, 10Ó and 12Ó in diameter) and AB remmeter were made inside a ANL 20-MeV electron Linac room. Calculations of the neutron detection time d...

The shielding calculations for high energy (>10 MV) linear accelerators must include the photoneutron production within the head of the accelerator. Procedures have been described to calculate the treatment room door shielding based on the neutron source strength (Q value) for a specific accelerator and energy combination. Unfortunately, there is currently little data in the literature stating ...