Efeito da radiação ionizante sobre plastissol de DOP/PVC utilizada como simulador de tecido em radioterapia

AUTOR(ES)
DATA DE PUBLICAÇÃO

1997

RESUMO

Recently a tissue simulator called bolus was developed at FEQ/UNICAMP, which is made of dioctyl phtalate and poly (vinyl chloride) (PVC/DOP). This bolus has the function of displacing the maximum dose to the skin and breast cancer. In this way the healthy tissues around the tumor are protected. The bolus composition is 23% (w/w) PVC and 76% (w/w) DOP with 1% (w/w) additives. Research at the Center for Women s Health (CAISM) of the Clinical Hospital of UNICAMP has shown that this material can be used as the tissue-equivalent of skin. In the present work, samples of this material were irradiated using both an electron beam and gamma rays at doses in the range of 0 to 75kGy. After irradiation the ionizing radiation effect on the molecular structure and the optical properties were studied. Changes in color were quantified by the yellowness index and diffusion reflectance spectroscopy. Structural changes were studied by Fourier transform infrared, mass spectroscopy and C ANTPOT. 13 nuclear magnetic resonance. The radicals formed were investigated by electron paramagnetic resonance. The results obtained show that the ionizing radiation promotes the formation of chromophoric groups, easily perceptible at 50kGy (electron beam) or at 75kGy (gamma rays); promotes the elimination of carbonyl groups from DOP radiolytic scission, which is more severe when the radiation is the electron beam, induces the formation of a small amount of conjugated polyenes as a result of PVC dehydrochlorination as well as radical formation as a consequence of the hemolytic scission of the chemical bonds of both DOP and PVC... Note: The complete abstract is available with the full electronic digital thesis or dissertations.

ASSUNTO(S)

radiação ionizante cancer - radioterapia polimeros na medicina radioterapia tumores

ACESSO AO ARTIGO

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