RESUMO
Computed tomography (CT) in the treatment position is currently indispensable for planning radiation therapy. Other imaging modalities, such as magnetic resonance imaging (MRI) and positron emission-tomography (PET), can be used to improve the definition of the tumour and/or healthy tissue but also to provide functional data of the target volume. Accurate image registration is essential for treatment planning, so MRI and PET scans should be registered at the planning CT scan. Hybrid PET/MRI scans with a hard plane can be used but pose the problem of the absence of CT scans. Finally, techniques for moving the patient on a rigid air-cushioned table allow PET/CT/MRI scans to be performed in the treatment position while limiting the patient's movements exist. At the same time, the advent of MRI-linear accelerator systems allows to redefine image-guided radiotherapy and to propose treatments with daily recalculation of the dose. The place of PET during treatment remains more confidential and currently only in research and prototype status. The same development of imaging during radiotherapy is underway in proton therapy.
Assuntos
Imageamento por Ressonância Magnética/métodos , Imagem Multimodal/métodos , Neoplasias/diagnóstico por imagem , Neoplasias/radioterapia , Tomografia por Emissão de Pósitrons/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Humanos , Imageamento por Ressonância Magnética/instrumentação , Imagem Multimodal/instrumentação , Tomografia por Emissão de Pósitrons/instrumentação , Terapia com Prótons/métodos , Planejamento da Radioterapia Assistida por Computador/instrumentaçãoRESUMO
The arrival of new hybrid radiotherapy machines with MRI or PET is announced as a milestone in radiotherapy management. Based on recent literature, we will describe the contribution of each of these modalities and the technological challenges that have already been or are still to be addressed.