Added value of combining VMAT with computer-selected patient-specific non-coplanar IMRT beams in radiotherapy for nasopharyngeal carcinoma and mediastinal lymphoma

Detalhes bibliográficos
Autor(a) principal: Leitão, Joana Marques da Silva
Data de Publicação: 2021
Tipo de documento: Dissertação
Idioma: eng
Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
Texto Completo: http://hdl.handle.net/10451/48309
Resumo: Tese de mestrado integrado em Engenharia Biomédica e Biofísica (Radiações em Diagnóstico e Terapia), Universidade de Lisboa, Faculdade de Ciências, 2021
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spelling Added value of combining VMAT with computer-selected patient-specific non-coplanar IMRT beams in radiotherapy for nasopharyngeal carcinoma and mediastinal lymphomaVMATIMRTPlaneamento automáticoCarcinoma nasofaríngeoLinfoma mediastinalTeses de mestrado - 2021Domínio/Área Científica::Engenharia e Tecnologia::Engenharia MédicaTese de mestrado integrado em Engenharia Biomédica e Biofísica (Radiações em Diagnóstico e Terapia), Universidade de Lisboa, Faculdade de Ciências, 2021Radiotherapy treatments can be coplanar, where all treatment beams are in a plane perpendicular to the longitudinal patient axis, or non-coplanar, allowing also other beam directions. On regular linear accelerators (linacs), which produce the high energy beams used in radiotherapy treatments, non-coplanar treatment is realized using patient couch rotations in between delivery of beams. Noncoplanar treatment considers a wider range of candidate beams, with a potential of improving patient dose distributions. However, non-coplanar treatments may be time-consuming as it involves couch rotations that may require technicians entering the treatment room prior to delivery of each beam to rotate the couch. In conventional manual planning for radiotherapy treatments, a dosimetrist has to steer the treatment planning system (TPS) to achieve a plan with adequate trade-offs between tumor coverage and protection of surrounding organs. This process is time-consuming and plan quality depends on the experience and allotted time of the dosimetrist. Automated planning (autoplanning) can optimize the planning process, resulting in high-quality plans, independent of the skills of planners. The Erasmus Medical Center (EMC), in Rotterdam, the Netherlands, has an in-house developed optimizer for automated multicriteria plan generation called Erasmus-iCycle. Erasmus-iCycle performs fully automated multi-criteria optimization (MCO) of both beam intensity profiles and beam angles. Erasmus-iCycle is driven by a ”wish-list”, describing constraints, requirements that must always be met, and prioritized treatment objectives with goals that should be met as much as possible, without violating the constraints. The output is a single Pareto-optimal plan with clinically favorable balances between coverage of the planning target volume (PTV), organs at risk (OAR) and healthy tissues. Erasmus-iCycle can generate plans for given beam arrangements or can identify the best beam arrangement for each patient using beam angle optimization (BAO). In this thesis, Erasmus-iCycle was used to investigate the added value of VMAT+ compared to other treatment approaches for two treatment sites: nasopharyngeal carcinoma (NPC) and mediastinal lymphoma (ML). VMAT+ is a specific approach for non-coplanar treatment in which coplanar volumetric modulated arc therapy (VMAT) is complemented with a few (<5) computer-optimized non-coplanar intensitymodulated (IMRT) beams. VMAT+ plans are generated using a coplanar VMAT as a base and adding non-coplanar beams consecutively, i.e. VMAT+1 is a coplanar VMAT combined with one patientoptimized IMRT beam, VMAT+2, a coplanar VMAT with the previously defined IMRT, plus another patient-optimized beam, selected as the best addition to the VMAT+1; and so on up to VMAT+5. NPC is a head and neck tumor, near many critical healthy organs. The first part of this study focused on a configuration of Erasmus-iCycle such that similar or superior plan quality as in the clinically applied plans was achieved. Subsequently, for 10 patients, VMAT and VMAT+ plans with 1-5 non-coplanar beams (total of 60 plans), were generated fully automatically using Erasmus-iCycle. Considering the OARs, VMAT+ plans, on average, outperformed VMAT. Plan quality increased with added number of beams, with lower Dmean for the parotids, submandibular glands and oral cavity, lower volumes receiving high doses overall and lower maximum dose of the spinal cord. OAR-sparing was patient-specific, for example for the parotids, all patients gain from VMAT+ plans, but the gain with VMAT+5 compared to VMAT ranges from 1 to 5 Gy. Also for the esophagus, improvements with VMAT+ are usually limited, but for one patient VMAT+1 reduces esophagus Dmean by 8 Gy. Considering plan quality and treatment time delivery, VMAT+3 was found to be, for most patients, the best compromise. For mediastinal lymphoma (ML) full-arc butterfly VMAT (FaB-VMAT), a published class solution made up of a coplanar VMAT arc and a non-coplanar partial-arc, was generated along with VMAT and VMAT+ plans. Twenty-five patients were included in the study, resulting in 175 plans. All 175 automatically generated treatment plans were clinically acceptable. VMAT+ and FaB-VMAT plans outperformed VMAT plans, but none of the VMAT+ was clearly superior to FaB-VMAT, nor the opposite was true. Added beams in VMAT+ resulted in lower Dmean doses for the heart and lungs, and lower V5 Gy and V20 Gy in the lungs and the patient. VMAT+ sparing was patient-specific, for example for lungs Dmean, all patients have reduced doses compared to VMAT, but the sparing with VMAT+5 varied from 1.5 to 0 Gy. FaB-VMAT had similar results to either VMAT+3, VMAT+4 or VMAT+5. FaB-VMAT has no-patient-specific beam arrangements which eliminated the planning time required for beam-angle selection in the VMAT+ technique and is a much faster treatment. In conclusion, VMAT+ improved VMAT plan quality for both treatment sites. For nasopharyngeal carcinoma, VMAT+3 was found to be the most appropriate treatment; for mediastinal lymphoma, both VMAT+5 and FaB-VMAT resulted in high-quality plans. However, VMAT+ was highly patient-specific and FaB-VMAT offers the best compromise between high plan quality and treatment time.Heijmen, BenMatela, Nuno Miguel de Pinto Lobo e,1978-Repositório da Universidade de LisboaLeitão, Joana Marques da Silva2021-06-02T16:53:41Z202120212021-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfhttp://hdl.handle.net/10451/48309TID:202692701enginfo: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:RCAAP2023-11-08T16:51:38Zoai:repositorio.ul.pt:10451/48309Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T22:00:13.486203Repositório 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 Added value of combining VMAT with computer-selected patient-specific non-coplanar IMRT beams in radiotherapy for nasopharyngeal carcinoma and mediastinal lymphoma
title Added value of combining VMAT with computer-selected patient-specific non-coplanar IMRT beams in radiotherapy for nasopharyngeal carcinoma and mediastinal lymphoma
spellingShingle Added value of combining VMAT with computer-selected patient-specific non-coplanar IMRT beams in radiotherapy for nasopharyngeal carcinoma and mediastinal lymphoma
Leitão, Joana Marques da Silva
VMAT
IMRT
Planeamento automático
Carcinoma nasofaríngeo
Linfoma mediastinal
Teses de mestrado - 2021
Domínio/Área Científica::Engenharia e Tecnologia::Engenharia Médica
title_short Added value of combining VMAT with computer-selected patient-specific non-coplanar IMRT beams in radiotherapy for nasopharyngeal carcinoma and mediastinal lymphoma
title_full Added value of combining VMAT with computer-selected patient-specific non-coplanar IMRT beams in radiotherapy for nasopharyngeal carcinoma and mediastinal lymphoma
title_fullStr Added value of combining VMAT with computer-selected patient-specific non-coplanar IMRT beams in radiotherapy for nasopharyngeal carcinoma and mediastinal lymphoma
title_full_unstemmed Added value of combining VMAT with computer-selected patient-specific non-coplanar IMRT beams in radiotherapy for nasopharyngeal carcinoma and mediastinal lymphoma
title_sort Added value of combining VMAT with computer-selected patient-specific non-coplanar IMRT beams in radiotherapy for nasopharyngeal carcinoma and mediastinal lymphoma
author Leitão, Joana Marques da Silva
author_facet Leitão, Joana Marques da Silva
author_role author
dc.contributor.none.fl_str_mv Heijmen, Ben
Matela, Nuno Miguel de Pinto Lobo e,1978-
Repositório da Universidade de Lisboa
dc.contributor.author.fl_str_mv Leitão, Joana Marques da Silva
dc.subject.por.fl_str_mv VMAT
IMRT
Planeamento automático
Carcinoma nasofaríngeo
Linfoma mediastinal
Teses de mestrado - 2021
Domínio/Área Científica::Engenharia e Tecnologia::Engenharia Médica
topic VMAT
IMRT
Planeamento automático
Carcinoma nasofaríngeo
Linfoma mediastinal
Teses de mestrado - 2021
Domínio/Área Científica::Engenharia e Tecnologia::Engenharia Médica
description Tese de mestrado integrado em Engenharia Biomédica e Biofísica (Radiações em Diagnóstico e Terapia), Universidade de Lisboa, Faculdade de Ciências, 2021
publishDate 2021
dc.date.none.fl_str_mv 2021-06-02T16:53:41Z
2021
2021
2021-01-01T00:00:00Z
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/10451/48309
TID:202692701
url http://hdl.handle.net/10451/48309
identifier_str_mv TID:202692701
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
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