SU-E-T-209: Four-Dimensional Gamma Method for Dose-Guided Radiotherapy

Medical Physics
Y WangY Wu

Abstract

The technique known as 'Gamma Evaluation Method' was an effective measure for dose distribution comparison; however, it could not be used for accurate real-time verification because of the unstable systematic factors. To reduce the errors induced by systematic factors and there was a requirement for real-time dose verification in Dose-guided Radiotherapy (DGRT), the formula of Gamma Method was improved, and four-dimensional(4D) Gamma Method was proposed. The gamma index, showing the deviation of two sets of dose distributions, should remove the error caused by different treatment delivery time to realize accurate real-time verification in Dose-guided Radiotherapy. Besides dose and distance, the variable of time, which was proportional to monitor unit (MU), was added to the formula. The criterion for acceptable distribution was generally defined as a tolerance of the dose, the distance and monitor unit. The algorithm was designed and realized using the tool of Microsoft Visual C++ 6.0. Two typical five beam treatment plans of Conformal Radiotherapy and Intensity-Modulated Radiotherapy were adopted to verify the algorithm. The two-dimensional (2D) ionization chamber MatriXX was used to measure the dose distribution. The verificat...Continue Reading

Related Concepts

Related Feeds

Buruli Ulcer

Buruli ulcer is a progressive disease of subcutaneous tissues caused by mycobacterium ulcerans. Here is the latest research.

© 2022 Meta ULC. All rights reserved