RESUMO
Purpose: Technological advancement in the treatment of cancer together with early detection and diagnosis have considerably improved the survival of breast cancer patients. On the other hand, the potential of patients developing side effects from cancer treatment are not negligible. Despite the progress that has been made in terms of early diagnosis, therapy, and survival, including improvements in the chemotherapeutic agents, radiation and molecular targeted therapies, cardiotoxicity of cancer therapy is still cause for concern. Radiation therapy for breast cancer is associated with increased risk of heart disease and myocardial infarction. Furthermore, the association of radiation therapy to chemotherapy is an important aspect to be considered in the development of cardiac disease, as this could play an additional role as a risk factor. Besides the heart effect, other side effects can be observed in the bone, ovary, uteri, and other organs. This paper aims to review the recent literature to present the current understanding of side effects associated with breast cancer treatment. The focus is on recent preclinical studies that have assessed potential changes in different organs that may be injured after breast cancer treatment, both due to both radiation and chemotherapy agents.Conclusion: Radiation-induced heart disease is one important side effect that must be considered during the treatment planning and patient follow-up. The cardiac damage can be potentialized when chemotherapy is associated to radiotherapy, and the literature findings indicate that heart fibrosis plays an important role at the radio-chemotherapy induced cardiac damage. Literature findings also showed important side effects at the bone, that can lead to ospeoporosis, due to the decrease of calcium, after radio or chemotherapy treatments. This decrease could be explained by the ovarian failure observed at rats after chemotherapy treatment. It is of great importance to acknowledge the complications originating from the treatment, so that new strategies can be developed. In this way, it will be possible to minimize side effects and improve the patients' quality of life.
Assuntos
Neoplasias da Mama/terapia , Animais , Antineoplásicos/efeitos adversos , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/radioterapiaRESUMO
The caspase-3-cleaved presence was evaluated in this study in the heart of irradiated rats, during the decline of ventricular function. Female Wistar rats were irradiated with a single dose of radiation (15 Gy) delivered directly to the heart and the molecular, histological and physiological evaluations were performed at thirteen months post-irradiation. The expressions of procollagen type I, TGF-ß1 and caspase-3-cleaved were analyzed using Western blotting. Cardiac structural and functional alterations were investigated by echocardiography and electron microscopy. In the irradiated group, the levels of procollagen type I, TGF-ß1 and caspase-3-cleaved are increased. Significant histological changes (degeneration of heart tissue and collagen deposition) and functional (reduced ejection fraction) were observed. Data suggest that the cardiac function decline after exposure to ionizing radiation is related, in part, to increased collagen and increased caspase-3-cleaved.
Assuntos
Caspase 3/metabolismo , Colágeno Tipo I/metabolismo , Coração/efeitos da radiação , Miocárdio/enzimologia , Fator de Crescimento Transformador beta1/metabolismo , Animais , Western Blotting , Relação Dose-Resposta à Radiação , Ecocardiografia , Ativação Enzimática/efeitos da radiação , Feminino , Microscopia Eletrônica de Transmissão , Miocárdio/ultraestrutura , Ratos , Ratos WistarRESUMO
This article presents the technical conditions necessary to establish appropriate radiation qualities for the calibration of the dosemeters used in the mammography detectors in the Laboratório de Ciências Radiológicas (LCR) from the Universidade do Estado do Rio de Janeiro. Tests were conducted to evaluate the homogeneity of the radiation field, scattering, half-value layers and system stability. The calibration method (substitution) is described in this work. A moderate alteration in filtration makes it possible to maintain the half-value layers within the limits recommended. The results indicate the adequacy of the LCR laboratory for the calibration of the dosemeters in the radiation qualities for mammography with an expanded uncertainty in the best measurement capability of ± 1.8 % (k = 2).
Assuntos
Calibragem/normas , Mamografia/instrumentação , Doses de Radiação , Radiometria/métodos , Feminino , Humanos , Mamografia/métodos , Padrões de Referência , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
Monte Carlo calculations of the absorbed dose at various points of a brachytherapy anthropomorphic phantom are presented. The phantom walls and internal structures are made of polymethylmethacrylate and its external shape was taken from a female Alderson phantom. A complete Fletcher-Green type applicator with the uterine tandem was fixed at the bottom of the phantom reproducing a typical geometrical configuration as that attained in a gynecological brachytherapy treatment. The dose rate produced by an array of five (137)Cs CDC-J type sources placed in the applicator colpostats and the uterine tandem was evaluated by Monte Carlo simulations using the code PENELOPE at three points: point A, the rectum, and the bladder. The influence of the applicator in the dose rate was evaluated by comparing Monte Carlo simulations of the sources alone and the sources inserted in the applicator. Differences up to 56% in the dose may be observed for the two cases in the planes including the rectum and bladder. The results show a reduction of the dose of 15.6%, 14.0%, and 5.6% in the rectum, bladder, and point A respectively, when the applicator wall and shieldings are considered.