Deformable versus rigid registration of PET-CT images for radiation treatment planning of head and neck and lung cancer patients: a retrospective dosimetric comparisonReport as inadecuate




Deformable versus rigid registration of PET-CT images for radiation treatment planning of head and neck and lung cancer patients: a retrospective dosimetric comparison - Download this document for free, or read online. Document in PDF available to download.

Radiation Oncology

, 9:50

Cancer imaging and new preclinical diagnostics in radiation oncologyClinical Radiation Oncology

Abstract

BackgroundThe purpose of this study is to evaluate the clinical impact of using deformable registration in tumor volume definition between separately acquired PET-CT and planning CT images.

MethodsTen lung and 10 head and neck cancer patients were retrospectively selected. PET-CT images were registered with planning CT scans using commercially available software. Radiation oncologists defined two sets of gross tumor volumes based on either rigidly or deformably registered PET-CT images, and properties of these volumes were then compared.

ResultsThe average displacement between rigid and deformable gross tumor volumes was 1.8 mm 0.7 mm with a standard deviation of 1.0 mm 0.6 mm for the head and neck lung cancer subjects. The Dice similarity coefficients ranged from 0.76-0.92 and 0.76-0.97 for the head and neck and lung subjects, respectively, indicating conformity. All gross tumor volumes received at least 95% of the prescribed dose to 99% of their volume. Differences in the mean radiation dose delivered to the gross tumor volumes were at most 2%. Differences in the fraction of the tumor volumes receiving 100% of the radiation dose were at most 5%.

ConclusionsThe study revealed limitations in the commercial software used to perform deformable registration. Unless significant anatomical differences between PET-CT and planning CT images are present, deformable registration was shown to be of marginal value when delineating gross tumor volumes.

KeywordsDeformable Registration PET-CT Treatment Planning AbbreviationsCTComputed tomograpy

PETPositron Emission Tomography

FDGFluorodeoxyglucose

RIRRigid image registration

DIRDeformable image regisgration

GTVGross tumor volume

IMRTIntensity modulated radiotherapy

DSCDice similarity coefficient

SUVStandardized Uptake Value

PTVPrimary target volume.

Electronic supplementary materialThe online version of this article doi:10.1186-1748-717X-9-50 contains supplementary material, which is available to authorized users.

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Author: Dominique Fortin - Parminder S Basran - Tanya Berrang - David Peterson - Elaine S Wai

Source: https://link.springer.com/







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