Related Experiment Video
Updated: Feb 12, 2026

Radiation Planning Assistant - A Streamlined, Fully Automated Radiotherapy Treatment Planning System
Published on: April 11, 2018
Evaluation of Dose Distribution at the Level of Electronic Portal Imaging Device using Treatment Planning System
Amene Bagheri1, Mehdi Momennezhad2, Shahrokh Nasseri3
1Department of Medical Physics, Mashhad University of Medical Sciences, Mashhad, Iran.
Background:
Treatment Planning Systems (TPS) are designed to calculate dose distributions within the CT imaging field of view. However, the Electronic Portal Imaging Device (EPID) is positioned outside this area, making it challenging to use standard TPS for dose calculations at the EPID level.
Objective:
The objective of this study is to present an innovative approach to address the limitations of TPS in calculating dose distribution at the EPID level.
Material And Methods:
In this retrospective quantitative study, the CT image was extended to the EPID level and imported into the TPS. 42 treatments were planned, and doses were calculated. The TPS doses were then compared with the measured doses obtained using an Ion Chamber (IC). The study also investigated the impact of field size, phantom thickness, and air gap for energies of 6, 10, and 15 MV.
Results:
The average, minimum, and maximum dose differences were 1.91%, 0.02%, and 5.79% when changing the field size from 5×5 cm2 to 20×20 cm2, 3.62%, 0.18%, and 6.91% when the phantom thickness changed from 10 to 30 cm, and 3.5%, 0.4%, and 7.46% when the air gap was varied from 30 to 60 cm respectively. 97% of all changes in IC values can be predicted through the linear relationship with TPS.
Conclusion:
The validated proposed method in this study, as an innovative approach, effectively addresses the limitation of TPS in calculating dose distribution at the EPID level. This can be used as a reference for comparing the measured dose obtained by EPID in dosimetric verification.
More Related Videos
09:41A Pipeline for 3D Multimodality Image Integration and Computer-assisted Planning in Epilepsy Surgery
Published on: May 20, 2016
07:57Positron Emission Tomography-based Dose Painting Radiation Therapy in a Glioblastoma Rat Model using the Small Animal Radiation Research Platform
Published on: March 24, 2022
Related Concept Videos
Hepatic Portal System
At its core, the hepatic portal vein is the result of a confluence of the superior and inferior mesenteric veins along with the splenic vein. Each of these veins has a unique role. The superior mesenteric vein is...
Sampling Plans
Random sampling is a method where each member of the population has an equal chance of being selected for the sample. It involves selecting individuals randomly, often using random number generators or lottery-type methods. For example, when analyzing the properties of a...
Electron Behavior
Electrons are negatively charged subatomic particles that are attracted to an orbit around the positively-charged nucleus of an atom. They reside in locations that are associated with energy levels called shells and are further organized into sub-shells and orbitals within each shell.
Electrons Orbit the Nucleus
Electrons are found in specific locations outside of the nucleus. The shell in which an electron resides indicates the general energy level of the electron: those closer to the...
Electron Affinity
Electron Orbital Model
The first shell is closest to the nucleus, and it has only one subshell with a single spherical orbital called the...
Dose Size and Dosing Frequency: Determination Methods