Document type
Academic documents
Document subtype
Master's dissertation
Title
Planeamento robusto para radioterapia com protões
Participants in the publication
Joana Gamboias Neves (Author)
Joana Dias (Supervisor)
Brígida Ferreira (Co-Supervisor)
Dep. Física
IBEB
Summary
Cancer is a global health problem that affects millions of people every year. Many oncologic patients are subjected to radiotherapy treatments, one of the possible treatment modalities for this disease. Within radiotherapy treatments, in the last decades, there has been an increasing interest in proton radiotherapy.\\\\nThe physical properties of protons enable dose distributions that are conformal and homogeneous to the target volume, and, simultaneously, deposit less dose in organs at risk. Consequently, there is the potential for an increase in tumor control probability as well as a decrease in the risk of secondary effects that occur by using ionizing radiation. However, as a disadvantage, proton radiotherapy is more sensitive to diverse sources of uncertainties, that can negatively affect the expected clinical outcomes. One of the possibilities to reduce the impact of uncertainties is taking them into consideration explicitly during the treatment planning process, which can be done by applying robust optimization methods. It is also possible that an appropriate choice of irradiation beam directions can influence the quality of the dose distribution. Therefore, robust optimization methods and beam angle optimization have a relevant impact in dose distribution and consequently on the quality of the treatment plan.\\\\nThe focus of this dissertation is to study robust methods for treatment planning in proton radiotherapy. In the first part of this dissertation, the impact of existing uncertainties in photon and proton radiotherapy was compared. The results clearly show that proton radiotherapy treatments are more sensitive to uncertainties than photon treatments.\\\\nIn the second part, a new robust fluence map optimization is described taking into explicit consideration uncertainties in the planning process. The obtained results lead to the conclusion that the developed approaches calculate clinically admissible treatment plans, that are also robust against uncertainties. Finally, beam angle optimization was applied with two different approaches, showing that it is possible to calculate a set of beam angles different from the ones usually used in clinical practice with improved outcomes.
Date of Publication
2022-07-11
Institution
FACULDADE DE CIÊNCIAS E TECNOLOGIA DA UNIVERSIDADE DE COIMBRA
Publication Identifiers