Evidence map›Paper›PMID 33849576›Full record

ArticleRadiation oncology (London, England)2021

Method of computing direction-dependent margins for the development of consensus contouring guidelines.

Liam S P Lawrence, Lee C L Chin, Rachel W Chan, Timothy K Nguyen, Arjun Sahgal, Chia-Lin Tseng, Angus Z Lau

Abstract read
In one paragraph

Article in Radiation oncology (London, England), 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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4 · The record

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5 · Who and what money

Authors and funding

7 authors.

Liam S P LawrenceDepartment of Medical Biophysics, University of Toronto, Toronto, ON, Canada.
Lee C L ChinDepartment of Medical Physics, Odette Cancer Centre, Toronto, ON, Canada.
Rachel W ChanPhysical Sciences Platform, Sunnybrook Research Institute, 2075 Bayview Ave., Toronto, M4N 3M5, ON, Canada.
Timothy K NguyenDepartment of Radiation Oncology, London Health Sciences Centre, Western University, London, ON, Canada.
Arjun SahgalDepartment of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, Canada.
Chia-Lin TsengDepartment of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, ON, Canada.
Angus Z LauDepartment of Medical Biophysics, University of Toronto, Toronto, ON, Canada. angus.lau@sri.utoronto.ca.ORCID http://orcid.org/0000-0002-9604-394X

Funding

Natural Sciences and Engineering Research Council of Canada CRD 507521-16Natural Sciences and Engineering Research Council of Canada RGPIN-2017-06596
6 · The paper itself

Abstract

backgroundClinical target volume (CTV) contouring guidelines are frequently developed through studies in which experts contour the CTV for a representative set of cases for a given treatment site and the consensus CTVs are analyzed to generate margin recommendations. Measures of interobserver variability are used to quantify agreement between experts. In cases where an isotropic margin is not appropriate, however, there is no standard method to compute margins in specified directions that represent possible routes of tumor spread. Moreover, interobserver variability metrics are often measures of volume overlap that do not account for the dependence of disagreement on direction. To aid in the development of consensus contouring guidelines, this study demonstrates a novel method of quantifying CTV margins and interobserver variability in clinician-specified directions.

methodsThe proposed algorithm was applied to 11 cases of non-spine bone metastases to compute the consensus CTV margin in each direction of intraosseous and extraosseous disease. The median over all cases for each route of spread yielded the recommended margins. The disagreement between experts on the CTV margin was quantified by computing the median of the coefficients of variation for intraosseous and extraosseous margins.

resultsThe recommended intraosseous and extraosseous margins were 7.0 mm and 8.0 mm, respectively. The median coefficient of variation quantifying the margin disagreement between experts was 0.59 and 0.48 for intraosseous and extraosseous disease.

conclusionsThe proposed algorithm permits the generation of margin recommendations in relation to adjacent anatomy and quantifies interobserver variability in specified directions. This method can be applied to future consensus CTV contouring studies.

Indexed as

Margins of ExcisionAlgorithmsBone and BonesConsensusHumansMedical InformaticsNeoplasm MetastasisObserver VariationRadiosurgeryRadiotherapy Planning, Computer-AssistedReproducibility of ResultsSoftwareClinical target volume marginsConsensus contouringInterobserver variabilityStereotactic body radiotherapy

Identifiers

PMID33849576
PMCPMC8045331

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