Award Date

December 2018

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Health Physics and Diagnostic Sciences

First Committee Member

Yu Kuang

Second Committee Member

Steen Madsen

Third Committee Member

Matthew Schmidt

Fourth Committee Member

Szu-Ping Lee

Number of Pages

49

Abstract

The purpose of this project is to build software that can programmatically analyze dosimteric images and reduce the QA time when performing gamma analysis at varying test criteria and evaluating the results of the Winston-Lutz test. The application leverages the Eclipse Scripting API (ESAPI) within the Eclipse Treatment planning system of Varian Medical Systems. The Portal Dosimetry Application of Eclipse is used to collect the image pixels. The pixels are then displayed in a Windows Presentation Foundation using Microsoft Visual Studio and C#.

The purpose of the Gamma Index pass rates software is to benchmark the Portal Dosimetry Application by analyzing an integrated image. However, the software allows for the user to test a range of parameters as opposed to one parameter at the time. The gamma values calculated with custom application were the same with the values calculated with Eclipse. This is because both software uses the same API. However, the custom application significantly reduces calculation time.

The purpose of the Winston-Lutz software is to programmatically analyze an integrated image and determine the isocenter wobble of the machine. Two methods were developed to calculate the isocenter wobble. A manually detect method and a auto detect method. The average error in calculating the isocenter wobble when using the manually detect method is 0.1 mm. The average error in calculating the isocenter wobble when using the auto detect method is 0.4mm.

This work indicates that computer software can be of significant importance when performing QA to check for the dosimetric output and the mechanical stability of the rotation axes of the clinical linear accelerator (linac).

Keywords

Gamma Analysis; Medical Physics; Winston-Lutz Test

Disciplines

Medicine and Health Sciences

Language

English


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