Title of presentation

2012 International Symposium on radiation Physics - ISRP 2012
Rio de Janeiro, RJ, Brazil, October 07-12, 2012
INTERNATIONAL RADIATION PHYSICS SOCIETY - IRPS


EVALUATION OF RADIOTHERAPY AND CHEMOTHERAPY EFFECTS IN BONE
MATRIX USING X-RAY MICROFLUORESCENCE
C. B. V. Andrade1,2,3*, C. Salata1,4, C. M. Silva1, S. C. Ferreira-Machado1,5, D. Braz6, A. P. Almeida6, L. P. Nogueira7, R. C. Barroso7, C. E. deAlmeida1 1. Laboratório de Ciências Radiológicas/UERJ/RJ – Rua São Francisco Xavier, 524 PHLC sl 136 – Maracanã – RJ – Brasil – cherleyborba@yahoo.com.br 2. Universidade Severino Sombra/USS/RJ – Av Expedicionário Osvaldo de Almeida Ramos, 280 – Centro – Vassouras – RJ - Brasil 3. Ultraestrutura e Biologia Tecidual/UERJ/RJ – Av 28 de Setembro, 87 Pavilhão Américo Piquet Carneiro 3ºAndar – Vila Isabel – RJ - Brasil 4. Laboratório de Morfometria e Morfologia Cardiovascular/UERJ/RJ - Av 28 de Setembro, 87 Pavilhão Américo Piquet Carneiro térreo – Vila Isabel – RJ - Brasil 5. Departamento de Biologia Geral/UFF/RJ - Outeiro de São João Batista, s/n - Niterói - 6. Laboratório de Instrumentação Nuclear/COPPE/UFRJ - Sala 133 - Bloco I - Centro de Tecnologia - Ilha do Fundão - RJ - Brasil 7. Instituto de Física/UERJ – Rua São Francisco Xavier, 524 Bl B sl 3019 – Maracanã – RJ - The most used treatment strategies for breast cancer (BC) are surgery, chemotherapy, and/or radiotherapy. Premenopausal women undergoing adjuvant chemotherapy BC treatment have significant bone loss from the first year after the treatment. This high bone mineral density loss can lead to an increased risk of fractures. Docetaxel associated with cyclophosphamide (TC) is a multidrug constantly used for BC treatment. Data from the "Women`s Health Initiative" show that postmenopausal BC survivors have a 15% greater risk of developing fractures than women without a history of BC. In this study, there were evaluated parameters involved in osteoporosis when rats were subjected to a chemotherapy regimen (TC) and/or irradiation (IR). Female Wistar rats, 03 months old, were divided into 3 groups: control (G1), TC+IR (G2) and IR (G3). The animals were euthanized 5 months after the end of treatment and their femora were excised and dissected. Uteri were also excised so that uterine mass could be evaluated. Reduction of uterus mass occurs due to reduction in estrogen levels, what is a good predictor of menopause. The uteri of these rats were collected and weighed. Statistical analyzes were performed using GraphPad Prism, and values were compared using ANOVA and Tukey post-hoc test. The obtained results showed that animals from G2 had a significant reduction (p<0.05) of uterine mass when compared to control. For bone matrix, sections of 10µm thick from different sites of femora were used for µXRF analysis at the National Laboratory of Synchrotron Light (Brazil). The qualitative analysis performed by µXRF showed that the animals from G2 presented iron in bone composition of the femora. This alteration was not observed in animals from G1 and G3 groups. These results suggest that early menopause occurs and osteoporosis begins, probably because of the absence, or reduced, production of estrogen. The presence of iron in G2 samples indicates the process of osteoporosis, as the iron is competitive with calcium, according to literature.

Source: http://www.cnen.gov.br/hs_isrp12/programa/parte1/C.%20B.%20V.%20Andrade.pdf