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- 4DCT versus 4DPET/CT na avaliação do movimento respiratório no planeamento da radioterapia no cancro do pulmão de não pequenas células: revisão da literaturaPublication . Dias, Paulo; Neves, Samuel; Raminhas Carapinha, Maria João; Caetano, MarcoIntrodução – Uma das abordagens terapêuticas no carcinoma do pulmão de não pequenas células (CPNPC) é a quimioterapia e radioterapia (RT) concomitante. O planeamento de RT pode ser realizado com base em diferentes técnicas de imagem, existindo vários fatores que podem influenciar a qualidade das mesmas, nomeadamente o movimento respiratório. Objetivos – Este estudo tem como objetivos: 1) avaliar a importância da 4DCT e da 4DPET/CT para a correção de movimento e definição do volume alvo no planeamento de RT para CPNPC; e 2) comparar a delimitação de volumes entre as técnicas PET/CT, 4DCT e 4DPET/CT, identificando as suas vantagens e limitações. Métodos – Revisão da literatura, recorrendo-se à metodologia PRISMA para a seleção de artigos nas bases de dados PubMed e Science Direct e outras fontes (b-on e Google Scholar). Foram considerados artigos publicados entre janeiro de 2014 e janeiro de 2020. Foram comparados volumes delimitados através de técnicas 3D e 4D, avaliando o impacto do movimento respiratório na aquisição de imagens e posterior planeamento de RT. Resultados – Obtiveram-se 230 artigos, mas apenas cinco foram elegíveis para estudo. As técnicas 4DCT e 4DPET/CT apresentaram melhores resultados, diminuindo os artefactos de movimento. Os volumes delimitados pelas várias técnicas em estudo foram semelhantes, apesar de se registarem pequenas variações quando a técnica 4D não é aplicada. Conclusão – Atualmente a 4DPET/CT apresenta melhores resultados na delimitação de volumes alvo para o planeamento de RT do que a técnica 4DCT.
- Applicability of MRI-only technique in external beam radiotherapy: dosimetric evaluation, IGRT, and quality assurance (a systematic review)Publication . Pereira, Daniel; Pereira, Luís; Barbosa, J.; Caetano, MarcoIntroduction: Magnetic Resonance Imaging (MRI) provides superior soft tissue contrast compared to planning Computed Tomography (pCT). Although pCT remains the standard method in radiotherapy planning due to its provision of electron density information required for dose calculations, the MRI-only technique can replace pCT by generating synthetic CTs (sCTs) that supply the necessary density data. Methods: A systematic literature review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The literature search was performed in April 2025 across the PubMed, Scopus, and Web of Science databases, applying inclusion and exclusion criteria defined using the PICOS model. The included studies were assessed using the "Appraising the Evidence: Reviewing Disparate Data Systematically" tool, and extracted data were synthesised in a narrative summary table. Results: A total of 41 studies were included, covering different anatomical regions. The studies reported non-significant differences in dose-volume histograms (DVH) between sCT and CT. Gamma analysis conformity evaluations showed pass rates >87.4 %. The deviations across various image registrations remained <2 mm for translational displacements and <1.2° for rotations. Discrepancies between sCT-CT and sCT-Cone Beam CT were ≤1 %. Conclusion: The MRI-only technique proved to be feasible for use in the central nervous system and pelvic regions, both in terms of dosimetry and image-guided verification. In head and neck oncology, the focus was exclusively on dosimetric planning. Further studies are required to validate and expand the applicability of this technique to other anatomical sites. Implications for practice: These findings reinforce the applicability and versatility of the MRI-only approach across multiple anatomical regions and therapeutic contexts, highlighting its potential to improve patient comfort and streamline clinical workflows.
- Structural findings obtained through optic coherence tomography and magnetic resonance in glaucoma: a systematic reviewPublication . Creado, Joana; Caetano, Marco; Camacho, PedroABSTRACT - Introduction: Optical coherence tomography (OCT) is essential in evaluating glaucomatous optic neuropathy (GON), particularly in asymptomatic stages, by analyzing retinal ganglion cells (RGCs) and retinal nerve fiber layers (RNFL). However, the relationship between magnetic resonance imaging (MRI) findings and structural biomarkers from OCT remains unclear. Objective: To study the association between MRI and OCT findings through a systematic review, aiming to clarify their relevance in the early identification of visual system changes in GON. Methods: Following PRISMA guidelines, a systematic review of the current literature was conducted using the PubMed, Scopus, and Cochrane Library databases, searching for Medical Subject Headings (MeSH) terms related to optical coherence tomography (OCT), spectral-domain, magnetic resonance imaging, and glaucoma. Initially, 719 articles were identified. Independently, two researchers screened for duplicates, applied eligibility criteria, and selected 28 articles for data extraction and evaluation. Results: Across the 28 selected articles, data from 1321 participants (781 GON and 540 controls) were analyzed. MRI structural findings were primarily associated with RNFL changes and visual field alterations, while metabolic findings appeared to correlate more with RGC changes. The most relevant MRI structural findings included a reduction in specific areas of the visual cortex and a decrease in the height and volume of the lateral geniculate nucleus. The most significant metabolic findings were indices of disruption and alterations in cerebral blood flow. Conclusions: The combined use of MRI and OCT structural findings shows potential for further exploration, especially in the early stages of the disease.