Related Experiment Video
Updated: Mar 23, 2026
09:14
Preparing a Celadonite Electron Source and Estimating Its Brightness
Published on: November 5, 2019
4.9K
Comparison of two programs in calculating electron output factors at extended source-surface distances
Yunfei Hu1, Jonathan Andrew Lambert1, Yang Wang1
1Department of Medical Physics, Radiation Oncology Institute, Sydney and Gosford, Australia.
Journal of Medical Physics
|April 7, 2016
Summary
Independent verification of radiotherapy monitor units (MUs) is crucial. eDatabook showed greater accuracy than RadCalc for output factors (OFs) at extended source-surface distances (SSDs), though RadCalc struggled with these calculations.
Area of Science:
- Medical Physics
- Radiation Oncology
- Radiotherapy Quality Assurance
Background:
- Accurate calculation of monitor units (MUs) is essential for safe radiotherapy.
- Independent verification of MUs is a critical quality assurance step.
- Discrepancies in output factors (OFs) can arise from different calculation methods in independent MU checking software, especially at extended source-surface distances (SSDs).
Purpose of the Study:
- To compare the accuracy of two independent MU checking software packages, RadCalc and eDatabook.
- To evaluate their performance in calculating output factors (OFs) at standard and extended SSDs.
- To identify potential limitations of these software packages in clinical radiotherapy settings.
Main Methods:
- Measured output factors (OFs) for electron cutouts on an Elekta Synergy linear accelerator at standard and extended SSDs (≥100 cm).
- Compared measured OFs with those calculated by RadCalc and eDatabook.
- Assessed the accuracy of each software package based on the deviation from measured values.
Main Results:
- eDatabook generally provided output factors (OFs) closer to measured values compared to RadCalc.
- RadCalc demonstrated inaccuracies at extended SSDs due to its reliance on effective-SSD curve assumptions.
- eDatabook showed improved accuracy at extended SSDs by employing linear interpolation, although it was unable to provide factors in two instances.
Conclusions:
- eDatabook offers a more accurate method for calculating output factors (OFs) at extended SSDs compared to RadCalc.
- The linear interpolation method used by eDatabook is advantageous for extended SSD calculations in radiotherapy.
- Further validation and potential improvements to RadCalc's algorithm for extended SSDs are warranted.
More Related Videos
10:23Author Spotlight: A Machine-Vision Approach to Transmission Electron Microscopy Workflows, Results Analysis and Data Management
Published on: June 23, 2023
3.6K
08:31Sample Preparation and Experimental Design for In Situ Multi-Beam Transmission Electron Microscopy Irradiation Experiments
Published on: June 27, 2022
2.4K
Related Concept Videos
01:25Calculation of Electric Flux
3.2K
Consider the electric field of an oppositely charged, parallel-plate system and an imaginary box between those plates. Let the bottom face of the box be ABCD, and the top face be FGHK. The electric field between the plates is uniform and points from the positive plate toward the negative plate. The calculation of this field's flux through the box's various faces shows that the net flux through the box is zero. Why does the flux cancel out here?
3.2K
01:20Atomic Emission Spectroscopy: Overview
4.2K
Atomic emission spectroscopy (AES) is an analytical technique used to determine the elemental composition of a sample by analyzing the light emitted from excited atoms. In AES, atoms in a sample are excited to higher energy levels by thermal energy from high-temperature sources, such as plasma, arcs, or sparks. When these excited atoms return to lower energy states, they emit light at specific wavelengths characteristic of each element. The resulting atomic emission spectrum, which consists of...
4.2K
01:19Thomson's e/m Experiment
7.5K
In a beam of charged particles created by a heated cathode, the particles move at different speeds. However, many applications need a beam with uniform particle speeds. An arrangement known as a velocity selector uses electric and magnetic fields to pick particles with a particular speed from the beam.
A particle with charge q, speed v, and mass m enters an area from the top, where the magnetic and electric fields are perpendicular both to the particle's motion and to one another. The magnetic...
A particle with charge q, speed v, and mass m enters an area from the top, where the magnetic and electric fields are perpendicular both to the particle's motion and to one another. The magnetic...
7.5K
01:29Atomic Emission Spectroscopy: Lab
779
AES is a powerful analytical technique, especially effective when used with plasma sources, producing abundant spectra in characteristic emission lines. The Inductively Coupled Plasma (ICP), in particular, yields superior quantitative analytical data due to its high stability, low noise, low background, and minimal interferences under optimal experimental conditions. However, newer air-operated microwave sources are emerging as promising alternatives that could be more cost-effective than...
779
01:22Atomic Emission Spectroscopy: Instrumentation
1.5K
The instrumentation of atomic emission spectrometry (AES) involves various components, including atomization devices that convert samples into gas-phase atoms and ions. There are two main types of atomization devices: continuous and discrete atomizers. Continuous atomizers, like plasmas and flames, introduce samples in a constant stream, while discrete atomizers inject individual samples using syringes or autosamplers. The most common discrete atomizer is the electrothermal atomizer.
1.5K
01:27Calculations of Electric Potential II
2.5K
An electric dipole is a system of two equal but opposite charges, separated by a fixed distance. This system is used to model many real-world systems, including atomic and molecular interactions. One of these systems is the water molecule, but only under certain circumstances. These circumstances are met inside a microwave oven, where electric fields with alternating directions make the water molecules change orientation. This vibration is equivalent to heat at the molecular level.
Consider a...
Consider a...
2.5K