Computed tomography imaging parameters for inhomogeneity correction in radiation treatment planning

Indra J. Das, Chee Wai Cheng, Minsong Cao, Peter A S Johnstone

Research output: Contribution to journalArticle

11 Scopus citations

Abstract

Modern treatment planning systems provide accurate dosimetry in heterogeneous media (such as a patient' body) with the help of tissue characterization based on computed tomography (CT) number. However, CT number depends on the type of scanner, tube voltage, field of view (FOV), reconstruction algorithm including artifact reduction and processing filters. The impact of these parameters on CT to electron density (ED) conversion had been subject of investigation for treatment planning in various clinical situations. This is usually performed with a tissue characterization phantom with various density plugs acquired with different tube voltages (kilovoltage peak), FOV reconstruction and different scanners to generate CT number to ED tables. This article provides an overview of inhomogeneity correction in the context of CT scanning and a new evaluation tool, difference volume dose-volume histogram (DVH), dV-DVH. It has been concluded that scanner and CT parameters are important for tissue characterizations, but changes in ED are minimal and only pronounced for higher density materials. For lungs, changes in CT number are minimal among scanners and CT parameters. Dosimetric differences for lung and prostate cases are usually insignificant (

Original languageEnglish (US)
Pages (from-to)3-11
Number of pages9
JournalJournal of Medical Physics
Volume41
Issue number1
DOIs
StatePublished - Jan 1 2016

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Keywords

  • Computed tomography artifact
  • computed tomography number
  • electron density
  • treatment planning

ASJC Scopus subject areas

  • Biophysics
  • Radiology Nuclear Medicine and imaging

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