RESUMO
Commercial radiochromic dye films have been used in recent years to quantify absorbed dose in several medical applications. In this study we present the characterisation of the GafChromic MD-55-2 dye film, a double sensitive layer film suitable for photon irradiation in brachytherapy applications. Dose measurements were carried out with a low dose rate 137Cs brachytherapy source, which produces very steep dose gradients in its vicinity, and therefore requires the capability of producing high spatial resolution isodose curves. Quantification of the dose rate in water per unit air kerma strength was obtained using a high-resolution transmission commercial scanner (Agfa DuoScan T1200 with the capability of digitising up to 600 x 1200 pixels per inch using 36 bits per pixel, together with optical density measurements. The Monte Carlo calculations and experimental measurements compared well in the 0-50 Gy dose interval used in this study.
Assuntos
Braquiterapia/métodos , Radioisótopos , Calibragem , Corantes , Humanos , Imagens de Fantasmas , Polimetil Metacrilato , Radiometria/métodos , ÁguaRESUMO
Using a probabilistic model with parameters from four radiotherapy protocols used in Mexican hospitals for the treatment of cervical cancer, we have calculated the distribution of dose to cells in peripheral blood of patients. Values of the mean dose to the lymphocytes during and after a 60Co treatment are compared to estimates from an in vivo chromosome aberration study performed on five patients. Calculations indicate that the mean dose to the circulating blood is about 2% of the tumor dose, while the mean dose to recirculating lymphocytes may reach up to 7% of the tumor dose. Differences up to a factor of two in the dose to the blood are predicted for different protocols delivering equal tumor doses. The data suggest mean doses higher than the predictions of the model.
Assuntos
Linfócitos/efeitos da radiação , Neoplasias do Colo do Útero/radioterapia , Aberrações Cromossômicas , Feminino , Raios gama , Humanos , Tecido Linfoide/efeitos da radiação , Dosagem RadioterapêuticaAssuntos
Neoplasias Ovarianas/radioterapia , Adulto , Idoso , Terapia Combinada , Estudos de Avaliação como Assunto , Feminino , Humanos , Histerectomia , Pessoa de Meia-Idade , Neoplasias Ovarianas/patologia , Neoplasias Ovarianas/cirurgia , Ovariectomia , Radioterapia/efeitos adversos , Estudos RetrospectivosAssuntos
Oncologia/tendências , Neoplasias/terapia , Adolescente , Adulto , Idoso , Antineoplásicos/uso terapêutico , Criança , Pré-Escolar , Terapia Combinada , Feminino , Previsões , Humanos , Imunoterapia , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Neoplasias/tratamento farmacológico , Neoplasias/radioterapia , Neoplasias/cirurgia , Gravidez , Medicina PreventivaRESUMO
The basic biological aspects in relation to cancer are reviewed and how this concepts has influenced the rational treatment of this disease. The best results achieved in the treatment of cancer are obtained because of the use of a more radical treatment. And for the patients with not very advanced stages, the results have been improved with the prophylactic treatment on those areas where the tumor usually gives metastases. However, an early diagnosis and the proper treatment are the best way to obtain relieve in this group of patients.