Alternative regimens for prostate cancer treatment using radiation therapy

Purpose/Objective: The purpose of this work was to determine biologically equivalent alternative regimens for the treatment of prostate cancer using External Beam Radiotherapy (EBRT) and Low Dose-Rate Brachytherapy (LDRBT) with 125I implants and to evaluate the sensitivity of these regimens to different sets of radiobiological parameters of the Linear-Quadratic (LQ) model.

Comparison of different breast planning techniques and algorithms for radiation therapy treatment

This work aims at investigating the impact of treating breast cancer using different radiation therapy (RT) techniques – forwardly-planned intensity-modulated, f-IMRT, inversely-planned IMRT and dynamic conformal arc (DCART) RT – and their effects on the whole-breast irradiation and in the undesirable irradiation of the surrounding healthy tissues. Two algorithms of iPlan BrainLAB treatment planning system were compared: Pencil Beam Convolution (PBC) and commercial Monte Carlo (iMC). Seven left-sided breast patients submitted to breast-conserving surgery were enrolled in the study. For each patient, four RT techniques – f-IMRT, IMRT using 2-fields and 5-fields (IMRT2 and IMRT5, respectively) and DCART – were applied. The dose distributions in the planned target volume (PTV) and the dose to the organs at risk (OAR) were compared analyzing dose–volume histograms; further statistical analysis was performed using IBM SPSS v20 software. For PBC, all techniques provided adequate coverage of the PTV. However, statistically significant dose differences were observed between the techniques, in the PTV, OAR and also in the pattern of dose distribution spreading into normal tissues. IMRT5 and DCART spread low doses into greater volumes of normal tissue, right breast, right lung and heart than tangential techniques. However, IMRT5 plans improved distributions for the PTV, exhibiting better conformity and homogeneity in target and reduced high dose percentages in ipsilateral OAR. DCART did not present advantages over any of the techniques investigated. Differences were also found comparing the calculation algorithms: PBC estimated higher doses for the PTV, ipsilateral lung and heart than the iMC algorithm predicted.

Implementation of proton therapy in the portuguese context of radiotherapy

Cancer is a national and international health care concern. It’s important to find strategies for early diagnosis as well as for the optimization of the various therapeutic options currently existing in Portugal. Cancer is the second leading cause of death in Portugal, the choice of this study, is due to the importance of radiotherapy approach in cancer treatment and because is the therapy used in 40% of oncology patients. Radiation therapy has evolve data technological level, that allows new treatment techniques that are more efficient and that also promotes greater professional satisfaction. The hadrons are charged particles, used in cancer therapy. These particles can bring a paradigm shift regarding the therapeutic approach in radiotherapy. The technique used is proton therapy, that reveal to be more accurate, efficacious and less toxic to surrounding tissue. Proton therapy may be a promising development in the field of oncology and how the treatment is given in radiotherapy. Although there is awareness of the benefits of proton therapy in oncology it’s also important to take in consideration the costs of these therapy, because they are considerably higher than conventional treatments of radiotherapy. Given the lack of a proton therapy service in Portugal, this study aims to be a documentary analysis of clinical records that will achieve the following objectives: to identify the number of cancer patients diagnosed in 2010 in Portugal and to calculate the estimated number of patients that could have been treated with proton therapy according to the Health Council of the Netherlands registration document.

Avaliação da distribuição de dose no CTV-PTV através de imagem guiada em doentes com carcinoma da próstata

Mestrado em Radioterapia.

Avaliação da margem do PTV em tumores ginecológicos com irradiação dos gânglios lomboaórticos, que realizaram IMRT

Mestrado em Radioterapia.

Avaliação dos desvios no posicionamento da IMRT prostática com marcadores fiduciais versus estruturas anatómicas

Mestrado em Radioterapia

Helical tomotherapy versus 3D conformal radiotherapy in dosimetric planning for patients with localized prostate cancer

Radiotherapy is one of the therapeutics selected for localized prostate cancer, in cases where the tumour is confined to the prostate, penetrates the prostatic capsule or has reached the seminal vesicles (T1 to T3 stages). The radiation therapy can be administered through various modalities, being historically used the 3D conformal radiotherapy (3DCRT). Other modality of radiation administration is the intensity modulated radiotherapy (IMRT), that allows an increase of the total dose through modulation of the treatment beams, enabling a reduction in toxicity. One way to administer IMRT is through helical tomotherapy (TH). With this study we intent to analyze the advantages of helical tomotherapy when compared with 3DCRT, by evaluating the doses in the organs at risk (OAR) and planning target volumes (PTV).

Radioterapia adaptativa: utilização do cone-beam computed tomography para o cálculo de dose em radioterapia

Mestrado em Radiações Aplicadas às Tecnologias da Saúde - Ramo de especialização: Terapia com Radiações

Relatório de estágio: tomoterapia

Mestrado em Radiações Aplicadas às Tecnologias da Saúde - Ramo de especialização: Terapia com Radiações

Minimizar o prolongamento do tratamento de radioterapia

Mestrado em Radiações Aplicadas às Tecnologias da Saúde - Ramo de especialização: Terapia com Radiações

Avaliação da eficácia da radioterapia paliativa no controlo da dor em doentes com metástases ósseas

A Radioterapia é um dos tratamentos disponíveis para tratar o cancro seja com intuito curativo ou paliativo. O objectivo da radioterapia paliativa consiste em controlar os sintomas apresentados pelos doentes com doença avançada, como por exemplo a dor provocada pela presença de metástases ósseas, que é o sintoma em estudo neste trabalho. A Radioterapia deve causar o mínimo de efeitos secundários e o mínimo desconforto possível aos doentes, não devendo aumentar a morbilidade, mas antes proporcionar maior qualidade de vida aos doentes. Recentemente, vários estudos investigaram a utilização da radioterapia em fim de vida, proporcionando uma linha orientadora nesta área, a partir das condições clínicas dos doentes submetidos a radioterapia perto do final da vida. A escolha do tema deste trabalho resulta de uma inquietação sentida no dia-a-dia, aquando da realização dos tratamentos de radioterapia a doentes paliativos com dor óssea e com mau estado geral. Exigindo a radioterapia um posicionamento e imobilização precisos e rigorosos pode, por vezes, causar algum desconforto aos doentes. No caso dos doentes com necessidades paliativas, nomeadamente com dor moderada a forte, é importante inferir acerca do real benefício de um tratamento que ao invés de promover alívio, lhes pode provocar mais dor e desconforto, indo contra às boas práticas preconizadas em cuidados paliativos. Considera-se que o tema é relevante para a melhoria dos cuidados prestados ao doente oncológico a realizar tratamentos de radioterapia, na medida em que permite realizar uma reflexão acerca da eficácia deste tratamento em fim de vida e sua aplicabilidade quando estamos perante doentes com prognóstico de vida limitado. O estudo em causa é um estudo descritivo exploratório, tendo sido realizada uma análise sistemática da informação contida nos processos electrónicos dos doentes, disponíveis na rede hospitalar, de acordo com os critérios de inclusão estabelecidos, no sentido de averiguar a eficácia do tratamento de radioterapia no alívio da dor. O estudo permitiu concluir que a radioterapia é um tratamento eficaz no controlo da dor em doentes com metástases ósseas, não vindo alterar as conclusões avançadas por outros estudos e outros autores internacionais. No entanto, é importante a realização de um prognóstico mais preciso na tomada de decisão terapêutica para que doentes que não vão beneficiar do tratamento de radioterapia possam ser referenciados para cuidados paliativos mais precocemente. Quanto à escolha do esquema terapêutico, o esquema de fracção única deveria ser mais comummente utilizado pela sua demonstrada eficácia, como o comprovam os diversos estudos referenciados neste trabalho.

Radiographers and radiation protection: education, training and CPD

The increasing use of ionizing radiation for medical purposes emphasizes the concern about safety and justification of using ionizing radiation. This is linked with the use of new and high-dose X-ray technology (particularly CT). According to the UNSCEAR 2010 Report the total number of diagnostic medical examinations (both medical and dental) is estimated to have risen from 2.4 billion (period 1991–1996) to 3.6 billion (period 1997– 2008) - a marked increase in collective doses. An appropriate use of technology aiming diagnostic or therapy and respecting the ALARA principle is a mandatory requisite to safely perform any radiological procedure. Radiation protection is thus, a concern of all specialists in the radiology field ( radiologists, radiographers, medical physicists, among other professional groups). The importance of education and training of these professionals in reducing patients’ doses while maintaining the desired level of quality in medical exposures, as well as precise therapeutic treatments is well recognized. Education, training and continuing professional development (CPD) constitute a triad pointing towards the radiographers’ development of competences in the radiation protection field. This presentation excludes the radiographer role and competences in the fields of ultrasonography and MRI.