Factors influencing conformity index in radiotherapy for non-small cell lung cancer.

Hdl Handle:
http://hdl.handle.net/10147/222695
Title:
Factors influencing conformity index in radiotherapy for non-small cell lung cancer.
Authors:
Brennan, Sinead M; Thirion, Pierre; Buckney, Steve; Shea, Carmel O; Armstrong, John
Affiliation:
Department of Radiation Oncology, St. Lukes Hospital, Dublin, Ireland. sinead.brennan09@gmail.com
Citation:
Factors influencing conformity index in radiotherapy for non-small cell lung cancer. 2010, 35 (1):38-42 Med Dosim
Journal:
Medical dosimetry : official journal of the American Association of Medical Dosimetrists
Issue Date:
2010
URI:
http://hdl.handle.net/10147/222695
DOI:
10.1016/j.meddos.2009.01.003
PubMed ID:
19931013
Abstract:
The radiotherapy conformity index (CI) is a useful tool to quantitatively assess the quality of radiotherapy treatment plans, and represents the relationship between isodose distributions and target volume. A conformity index of unity implies high planning target volume (PTV) coverage and minimal unnecessary irradiation of surrounding tissues. We performed this analysis to describe the CI for lung cancer 3-dimensional conformal radiotherapy (3DCRT) and to identify clinical and technical determinants of CI, as it is not known which factors are associated with good quality 3D conformal radiotherapy treatment planning. Radiotherapy treatment plans from a database of 52 patients with inoperable Stage 1 to 3b lung cancer, on a hypofractionated 3DCRT trial were evaluated. A CI was calculated for all plans using the definition of the ICRU 62:CI = (TV/PTV), which is the quotient of the treated volume (TV) and the PTV. Data on patient, tumor, and planning variables, which could influence CI, were recorded and analyzed. Mean CI was 2.01 (range = 1.06-3.8). On univariate analysis, PTV (p = 0.023), number of beams (p = 0.036), medial vs. lateral tumor location (p = 0.016), and increasing tumor stage (p = 0.041) were associated with improved conformity. On multiple regression analysis, factors found to be associated with CI included central vs. peripheral tumor location (p = 0.041) and PTV size (p = 0.058). The term 3DCRT is used routinely in the literature, without any indication of the degree of conformality. We recommend routine reporting of conformity indices. Conformity indices may be affected by both planning variables and tumor factors.
Item Type:
Article
Language:
en
MeSH:
Aged; Aged, 80 and over; Carcinoma, Non-Small-Cell Lung; Female; Humans; Lung Neoplasms; Male; Middle Aged; Radiometry; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted; Radiotherapy, Conformal; Reproducibility of Results; Sensitivity and Specificity
ISSN:
1873-4022

Full metadata record

DC FieldValue Language
dc.contributor.authorBrennan, Sinead Men_GB
dc.contributor.authorThirion, Pierreen_GB
dc.contributor.authorBuckney, Steveen_GB
dc.contributor.authorShea, Carmel Oen_GB
dc.contributor.authorArmstrong, Johnen_GB
dc.date.accessioned2012-05-09T10:18:07Z-
dc.date.available2012-05-09T10:18:07Z-
dc.date.issued2010-
dc.identifier.citationFactors influencing conformity index in radiotherapy for non-small cell lung cancer. 2010, 35 (1):38-42 Med Dosimen_GB
dc.identifier.issn1873-4022-
dc.identifier.pmid19931013-
dc.identifier.doi10.1016/j.meddos.2009.01.003-
dc.identifier.urihttp://hdl.handle.net/10147/222695-
dc.description.abstractThe radiotherapy conformity index (CI) is a useful tool to quantitatively assess the quality of radiotherapy treatment plans, and represents the relationship between isodose distributions and target volume. A conformity index of unity implies high planning target volume (PTV) coverage and minimal unnecessary irradiation of surrounding tissues. We performed this analysis to describe the CI for lung cancer 3-dimensional conformal radiotherapy (3DCRT) and to identify clinical and technical determinants of CI, as it is not known which factors are associated with good quality 3D conformal radiotherapy treatment planning. Radiotherapy treatment plans from a database of 52 patients with inoperable Stage 1 to 3b lung cancer, on a hypofractionated 3DCRT trial were evaluated. A CI was calculated for all plans using the definition of the ICRU 62:CI = (TV/PTV), which is the quotient of the treated volume (TV) and the PTV. Data on patient, tumor, and planning variables, which could influence CI, were recorded and analyzed. Mean CI was 2.01 (range = 1.06-3.8). On univariate analysis, PTV (p = 0.023), number of beams (p = 0.036), medial vs. lateral tumor location (p = 0.016), and increasing tumor stage (p = 0.041) were associated with improved conformity. On multiple regression analysis, factors found to be associated with CI included central vs. peripheral tumor location (p = 0.041) and PTV size (p = 0.058). The term 3DCRT is used routinely in the literature, without any indication of the degree of conformality. We recommend routine reporting of conformity indices. Conformity indices may be affected by both planning variables and tumor factors.en_GB
dc.language.isoenen
dc.rightsArchived with thanks to Medical dosimetry : official journal of the American Association of Medical Dosimetristsen_GB
dc.subject.meshAged-
dc.subject.meshAged, 80 and over-
dc.subject.meshCarcinoma, Non-Small-Cell Lung-
dc.subject.meshFemale-
dc.subject.meshHumans-
dc.subject.meshLung Neoplasms-
dc.subject.meshMale-
dc.subject.meshMiddle Aged-
dc.subject.meshRadiometry-
dc.subject.meshRadiotherapy Dosage-
dc.subject.meshRadiotherapy Planning, Computer-Assisted-
dc.subject.meshRadiotherapy, Conformal-
dc.subject.meshReproducibility of Results-
dc.subject.meshSensitivity and Specificity-
dc.titleFactors influencing conformity index in radiotherapy for non-small cell lung cancer.en_GB
dc.typeArticleen
dc.contributor.departmentDepartment of Radiation Oncology, St. Lukes Hospital, Dublin, Ireland. sinead.brennan09@gmail.comen_GB
dc.identifier.journalMedical dosimetry : official journal of the American Association of Medical Dosimetristsen_GB
dc.description.provinceLeinsteren
All Items in Lenus, The Irish Health Repository are protected by copyright, with all rights reserved, unless otherwise indicated.