The purpose of this study was to investigate the effect dose perturbations for two metallic spinal screw implants in proton beam therapy perpendicular and parallel geometry. A 5.5 mm (diameter) by 45 (length) stainless steel (SS) a 35 titanium (Ti) commonly used fixation were CT‐scanned hybrid phantom water solid water. CT data processed with an orthopedic metal artifact reduction (O‐MAR) algorithm. Treatment plans generated each oriented, first then perpendicular, longitudinal axis screw....

Abstract Purpose/Objective(s) To describe a log file–based patient‐specific quality assurance (QA) method and develop an in‐house tool for system performance tracking dose reconstruction in pencil‐beam scanning proton therapy that can be used pre‐treatment plan review. Materials/Methods The software extracts beam‐specific information from the treatment delivery file automatically compares monitor units (MU), lateral position, size of each spot against intended values to identify any...

PRESAGETM dosimeter has been proved useful for 3D dosimetry in conventional photon therapy and IMRT [1–5]. Our objective is to examine the use of verification depth dose distribution proton beam therapy. Three samples were irradiated with a 79 MeV un-modulated beam. Percent profile measured from compared data obtained water phantom using parallel plate Advanced Markus chamber. The Bragg-peak position determined within 2 mm measurements water. shows highly linear response dose. However, also...

Purpose: The main purpose of this study is to perform a treatment planning on synchronous bilateral non-small cell lung cancer case using three modalities: uniform scanning proton therapy, RapidArc, and intensity modulated radiation therapy (IMRT). Methods : maximum projection (MIP) images obtained from the 4 dimensional-computed tomography (4DCT) scans were used for delineation tumor volumes in left right lungs. average 4D-CT was among all modalities with identical patient contouring goal....

For proton beam therapy, CT imaging is required to calculate dose based on pixel values of relative stopping power (RSP). The variation among CT-scanners and the phantom used derive relationship number-electron density-RSP has not been investigated. Using RMI phantoms, 18 scanners a Tomotherapy unit, Hounsfield unit (HU) variations associated dosimetric uncertainty were HU was within one standard deviation (SD) average for 14 out 15 tested with same phantoms. high density materials (>400 HU)...

Abstract Introduction The purpose of this study was to evaluate the dosimetric and radiobiological impact intensity modulated proton therapy ( IMPT ) RapidArc planning for high‐risk prostate cancer with seminal vesicles. Methods Ten cases were included in retrospective study. For each case, plans generated using multiple field optimisation MFO technique (two fields) XiO treatment system TPS ), whereas double‐arc full arcs) Eclipse . optimised a total prescription dose 79.2 Gy (relative...

When iodinated contrast is administered during CT simulation, standard practice requires a separate non-contrast for dose calculation. The objective of this study to validate our hypothesis that since iodine affects Hounsfield units (HUs) more than electron density (ED), the information from post-contrast dual-layer (DLCT) would be sufficient accurate calculation both photon and proton therapy.10 pediatric patients with abdominal tumors underwent DLCT scans before after administration...

The residues of fipronil and its metabolites in chicken eggs pose a threat to human health, so regular monitoring is necessary. However, the pretreatments existing detection methods are complex time-consuming. A simple streamlined pretreatment method needed improve efficiency.A rapid, efficient, facile approach employing quick, easy, cheap, effective, rugged, safe (QuEChERS) with online solid-phase extraction liquid chromatography tandem Q Exactive Orbitrap high-resolution mass spectrometry...

The purpose of this study was to devise a simple semi-empirical model estimate the range shift in clinical practices with high-Z inhomogeneity proton beam. A utilizing logarithmic dependence on Z stopping power from Bohr's classical approach has been developed calculate due presence inhomogeneity. Range metallic plates atomic number various thicknesses were measured water using parallel plate ionization chamber and calculated FLUKA Monte Carlo code. shifts for bone polymethyl methacrylate...

Purpose: Small field dosimetry is challenging that impacts patient specific QA in proton beam therapy due to detector size, aperture scattering and disequilibrium. Therefore, it urgent develop an accurate efficient method quantify the uncertainty of 3D small fields. This study investigated feasibility using a new formula PRESAGE® for irregular therapy. Methods: Three cylindrical shape dosimeters (10 cm or 4 diameter, 6 length) (C304H510N20O71SBr) were irradiated with three fields (field size...

We would like to correct a typographical error. In the last paragraph of Page N296, line 4, it should read 'α =1.2269, β = -0.9446, γ 1.1046 and δ -0.004'

Purpose: This study provides an overview of the design and commissioning Monte Carlo (MC) model spot‐scanning proton therapy nozzle its implementation for patient plan simulation. Methods: The Hitachi PROBEAT V scanning was simulated based on vendor specifications using TOPAS extension Geant4 code. FLUKA MC simulation also utilized to provide supporting data main Validation performed provided measurements collected during acceptance/commissioning machine. Actual plans CT treatment geometry...

Abstract Purpose/objective(s) Surface‐guided radiation therapy (SGRT) can track the patient surface noninvasively to complement radiographic image‐guided with a standard 3‐camera system and single radiation/image isocenter. Here we report commissioning of novel SGRT that monitors three imaging isocenters locations in proton half‐gantry room unique 5‐camera configuration. Materials/methods The has image isocenters, designated ISO‐0, ISO‐1, ISO‐2, cover various anatomical sites via robotic...

This study aimed to develop a Monte Carlo (MC) framework for commissioning the narrow proton beams (spot size sigma, 5.2 mm 2 at isocenter 69.4 MeV-221.3 MeV main beam option and 4.1 1.3 minibeam respectively) of synchrotron-based therapy system design an independent absolute dose calculation engine intensity-modulated treatments. A (Hitachi PROBEAT-V) was simulated using divergent convergent models nozzle entrance. The innovative source weighting scheme MC simulation with TOPAS (TOol...

Purpose : To investigate an IC Profiler for clinical proton dosimetry QA. Methods and Materials: An (model 1122) (Sun Nuclear Corporation, Melbourne, FL) consisting of four linear arrays (X, Y, two diagonals) with 251 vented ion chambers was investigated. The chamber has 2.6 mm effective collection width 0.9 g/cm 2 inherent buildup. It irradiated a beam 16 cm penetration depth at 11 corresponding to the middle 10 spread‐out Bragg peak (SOBP) 10‐cm diameter circular field using uniform...

The application of the Reaction Monte Carlo (RxMC) algorithm to standard textbook problems in chemical reaction equilibria is discussed. RxMC method a molecular simulation for studying equilibrium properties reactive systems, and therefore provides opportunity develop computer-based "experiments" analysis wide range reactions. As conditions can be precisely controlled these simulations, students rather easily perform "virtual experiments", then compare resulting compositions, extents...

Purpose: The effect of dose calculation grid size for highly conformal proton planning is evaluated the first time. Our goal to find optimal different cases increase treatment efficiency while maintaining accuracy within clinical tolerance. Methods: Four head& neck, prostate, lung and CSI are studied calculated at three sizes (1 mm, 3 5 mm). To further understand accuracy, a phantom simulating with small fields large measured EBT films. results compared in form point profiles regions low...