Robustness of photon dose distributions against intra and inter-fraction anatomical changes for whole lung irradiation

Detalhes bibliográficos
Autor(a) principal: Piedade, Mariana Silva Pereira Fialho da
Data de Publicação: 2022
Tipo de documento: Dissertação
Idioma: eng
Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
Texto Completo: http://hdl.handle.net/10451/54234
Resumo: Tese de Mestrado Integrado, Engenharia Biomédica e Biofísica (Radiações em Diagnóstico e Terapia ) Universidade de Lisboa, Faculdade de Ciências, 2022
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spelling Robustness of photon dose distributions against intra and inter-fraction anatomical changes for whole lung irradiationIrradiação total do pulmãoradioterapia de fotõesalterações anatómicas por intrafraçãoalterações anatómicas por interfraçãoTeses de mestrado - 2022Departamento de FísicaTese de Mestrado Integrado, Engenharia Biomédica e Biofísica (Radiações em Diagnóstico e Terapia ) Universidade de Lisboa, Faculdade de Ciências, 2022Approximately 400 000 children are diagnosed with cancer every year, with the most common types of childhood cancers being leukemia, lymphoma, brain and solid tumors. Moreover, 10-40% of children with solid tumors present lung metastases at the time of diagnosis. Whole lung irradiation (WLI) is a treatment option for pediatric patients with lung metastases that develop from solid tumors like Ewing’s sarcoma (ES), rhabdomyosarcoma, and Wilms’ tumor (WT). However, during treatment delivery, intra and inter-fraction anatomical changes might occur and can greatly affect treatment outcome. These changes can either cause underdosages of the target volume, or overdosage of surrounding organs at risk (OARs). Since growing lung tissue is more sensitive to radiation, avoiding the irradiation of OARs while maintaining target coverage is of utmost importance. Thus, there is the need to ensure that a treatment plan is robust, which is accomplished if the planned and delivery dose distributions agree even in the presence of uncertainties. To evaluate how anatomical changes affect the treatment outcome when delivering WLI to pediatric patients, this thesis comprises a study of robustness of photon dose distributions against intra and inter-fraction anatomical changes. The present study includes treatment plans of 21 pediatric patients that received WLI at University Medical Center Utrecht. The robustness evaluation was performed against intra and inter-fraction anatomical changes. Intra-fraction changes were evaluated by recalculating the original plan on the two extreme breathing phases – maximum inhalation and maximum exhalation. Conversely, inter-fraction changes were evaluated by calculating the fractional dose on the daily cone-beam computed tomography (CBCT) images acquired before treatment and accumulating the resulting dose distributions. The recalculated plans were then compared to the original dose distribution. Overall results of the study demonstrated no clinically relevant differences in terms of mean internal target volume (ITV) coverage of the lungs. However, hot spot values differed significantly for three patients. The differences observed for the V107% were due to diaphragm position shifts (two patients) and electron density (ED) changes within the lung ITV (one patient). Coverage and hot spots of metastases presented clinically relevant differences when considering the extreme breathing phases, as well as the registered-CTs. This was due to differences in ED within the metastases and position variations in relation to surrounding structures (like the heart or ribs). However, these changes were observed for the PTV only, while ITV coverage remained around 100% on all plans. OAR dose values were robust against intra and inter-fraction anatomical changes, with no clinically relevant differences to report. In conclusion, the recalculated WLI plans are considered robust against intra and inter-fraction anatomical changes when taking into consideration average results. However, some clinically relevant differences were identified per patient, which require further attention and improvement in future treatment plans.Seravalli, EnricaConceição, RaquelRepositório da Universidade de LisboaPiedade, Mariana Silva Pereira Fialho da2022-08-30T14:55:28Z202220222022-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfhttp://hdl.handle.net/10451/54234enginfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2023-11-08T17:00:38Zoai:repositorio.ul.pt:10451/54234Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T22:05:09.199428Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse
dc.title.none.fl_str_mv Robustness of photon dose distributions against intra and inter-fraction anatomical changes for whole lung irradiation
title Robustness of photon dose distributions against intra and inter-fraction anatomical changes for whole lung irradiation
spellingShingle Robustness of photon dose distributions against intra and inter-fraction anatomical changes for whole lung irradiation
Piedade, Mariana Silva Pereira Fialho da
Irradiação total do pulmão
radioterapia de fotões
alterações anatómicas por intrafração
alterações anatómicas por interfração
Teses de mestrado - 2022
Departamento de Física
title_short Robustness of photon dose distributions against intra and inter-fraction anatomical changes for whole lung irradiation
title_full Robustness of photon dose distributions against intra and inter-fraction anatomical changes for whole lung irradiation
title_fullStr Robustness of photon dose distributions against intra and inter-fraction anatomical changes for whole lung irradiation
title_full_unstemmed Robustness of photon dose distributions against intra and inter-fraction anatomical changes for whole lung irradiation
title_sort Robustness of photon dose distributions against intra and inter-fraction anatomical changes for whole lung irradiation
author Piedade, Mariana Silva Pereira Fialho da
author_facet Piedade, Mariana Silva Pereira Fialho da
author_role author
dc.contributor.none.fl_str_mv Seravalli, Enrica
Conceição, Raquel
Repositório da Universidade de Lisboa
dc.contributor.author.fl_str_mv Piedade, Mariana Silva Pereira Fialho da
dc.subject.por.fl_str_mv Irradiação total do pulmão
radioterapia de fotões
alterações anatómicas por intrafração
alterações anatómicas por interfração
Teses de mestrado - 2022
Departamento de Física
topic Irradiação total do pulmão
radioterapia de fotões
alterações anatómicas por intrafração
alterações anatómicas por interfração
Teses de mestrado - 2022
Departamento de Física
description Tese de Mestrado Integrado, Engenharia Biomédica e Biofísica (Radiações em Diagnóstico e Terapia ) Universidade de Lisboa, Faculdade de Ciências, 2022
publishDate 2022
dc.date.none.fl_str_mv 2022-08-30T14:55:28Z
2022
2022
2022-01-01T00:00:00Z
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/masterThesis
format masterThesis
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://hdl.handle.net/10451/54234
url http://hdl.handle.net/10451/54234
dc.language.iso.fl_str_mv eng
language eng
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.source.none.fl_str_mv reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
instacron:RCAAP
instname_str Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
instacron_str RCAAP
institution RCAAP
reponame_str Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
collection Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
repository.name.fl_str_mv Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
repository.mail.fl_str_mv
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