Accounting for respiratory motion in partial breast intensity modulated radiotherapy during treatment planning: A new patient selection metric.
Abstract: Purpose: External beam partial breast irradiation intensity modulated radiotherapy (PBI IMRT) plans experience degradation in coverage and dose homogeneity when delivered during respiration. We examine which characteristics of the breast and seroma result in unacceptable plan degradation d...
| Publicado en: | European Journal of Cancer Vol. 50; no. 11; pp. 1872 - 1880 |
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| Autores principales: | , , |
| Formato: | research Journal Article |
| Publicado: |
Pergamon Press - An Imprint of Elsevier Science
Jul2014
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| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=103958964&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 103958964 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 09598049 1VW jtl: European Journal of Cancer issn: 09598049 maglogo: N pubinfo: dt: Jul2014 vid: 50 iid: 11 pid: 2410 pub: Pergamon Press - An Imprint of Elsevier Science artinfo: ui: 103958964 96446755 10.1016/j.ejca.2014.04.016 NLM24835033 103958964 ppf: 1872 ppct: 8 formats: tig: atl: Accounting for respiratory motion in partial breast intensity modulated radiotherapy during treatment planning: A new patient selection metric. aug: au: Quirk, Sarah Conroy, Leigh Smith, Wendy L affil: Department of Physics and Astronomy, University of Calgary, Calgary, AB, Canada; Department of Medical Physics, Tom Baker Cancer Centre, Calgary, AB, Canada sug: subj: Respiration Evaluation Radiotherapy, Conformal Breast Neoplasms Radiotherapy Human Patient Selection Research Methodology ab: Abstract: Purpose: External beam partial breast irradiation intensity modulated radiotherapy (PBI IMRT) plans experience degradation in coverage and dose homogeneity when delivered during respiration. We examine which characteristics of the breast and seroma result in unacceptable plan degradation due to respiration. Methods: Thirty-six patient datasets were planned with inverse-optimised PBI IMRT. Population respiratory data were used to create a probability density function. This probability density function (PDF) was convolved with the static plan fluences to calculate the delivered dose with respiration. To quantify the difference between static and respiratory plan quality, we analysed the mean dose shift of the target dose volume histogram (DVH), the dose shift at 95% of the volume and the dose shift at the hotspot to 2cm3 of the volume. We explore which patient characteristics indicate a clinically significant degradation in delivered plan quality due to respiration. Results: Dose homogeneity constraints, rather than dosimetric coverage, were the limiting factors for all patient plans. We propose the dose evaluation volume-to-planning target volume (DEV-to-PTV) ratio as a delineating metric for identifying patient plans that will be more degraded by respiratory motion. The DEV-to-PTV ratio may be a more robust metric than ipsilateral breast volume because the seroma volume is contoured more consistently between physicians and clinics. Conclusions: For patients with a DEV-to-PTV ratio less than 55% we recommend either not using PBI IMRT or employing motion management. Small DEV-to-PTV ratios occur when the seroma is close to inhomogeneities (i.e. air/lung), which exacerbates the dosimetric effect of respiratory motion. For small breast sizes it is unlikely that the DEV-to-PTV ratio will meet these criteria. pubtype: Academic Journal doctype: research Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
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