Background: The aim of this study was to develop and implement a Monte Carlo framework for evaluation of patient specific out-of-field organ equivalent dose (OED). Materials and Methods: Dose calculations were performed using a Monte Carlo-based model of Oncor linac and tomographic phantoms. Monte Carlo simulations were performed using EGSnrc user codes. Dose measurements were performed using r...

Background: Stereotactic radiosurgery is an important clinical tool for the treatment of small lesions in the brain, including benign conditions, malignant and localized metastatic tumors. A dosimetry study was performed for Elekta ‘Synergy S ’ as a dedicated Stereotactic radiosurgery unit, capable of generating circular radiation fields with diameters of 1-5 cm at isocentre using the BEAM/EGS4...

Purpose This prospective study is, to our knowledge, the first report of daily adaptive radiation therapy (ART) for head and neck cancer (HNC) using a 1.5T magnetic resonance imaging-linear accelerator (MR-linac) with particular focus on safety feasibility dosimetric results an online rigid registration-based adapt position (ATP) workflow. Methods Materials Ten patients HNC re...

Monte Carlo simulation of linear accelerators (linacs) depends on the accurate geometrical description of the linac head. The geometry of the Varian TrueBeam linac is not available to researchers. Instead, the company distributes phase-space files of the flattening-filter-free (FFF) beams tallied at a plane located just upstream of the jaws. Yet, Monte Carlo simulations based on third-party tal...

introduction electron linear accelerator (linac) can be used for neutron production in boron neutron capture therapy (bnct). bnct is an external radiotherapeutic method for the treatment of some cancers. in this study, varian 2300 c/d linac was simulated as an electron accelerator-based photoneutron source to provide a suitable neutron flux for bnct. materials and methods photoneutron sources w...

background: understanding of the incident electron energy and angular distributions from clinical electron accelerators (linacs) is important for dosimetry and treatment planning. the most important goals of this study were to evaluate the energy fluence and angular distributions of electron beams from a neptun 10pc linac using the monte carlo (mc) code. materials and methods: the linac electro...

Objective The aim of the present study is to simulate 6 MV and 18 MV photon beam energies of a Siemens Primus Plus medical linear accelerator (Linac) and to verify the simulation by comparing the results with the measured data. Methods The main components of the head of Siemens Primus Plus linac were simulated using MCNPX Monte Carlo (MC) code. To verify the results, experimental data of perc...

In layered and blocky rock slopes, toppling failure is a common mode of instability that may occur in mining engineering. If this type of slope failure occurs as a consequence of another type of failure, it is referred to as the secondary toppling failure. “Slide-head-toppling” is a type of secondary toppling failures, where the upper part of the slope is toppled as a consequence of a semi-circ...

The DAVID is a transparent, multi-wire transmission-style detector that attaches to a linear accelerator (linac) collimator for use as an in vivo detector. Currently, the normal method for using the DAVID is to measure a signal at the time of phantom-based pretreatment verification and use that signal as a baseline to compare with in vivo measurements for subsequent treatment fractions. The dev...

This study investigates the feasibility and applicability of cone beam CT for a megavoltage therapeutic LINAC. A Rando head phantom was irradiated using the 15 MV beam of a Varian 2100C LINAC at MSKCC for gantry angles from -102° to 102° with a 2° increment. The projection image for each gantry angle was obtained using a Varian Mark II EPID. Reference images without phantom were also collected ...