ISSUES IN RADIOTHERAPY PRACTICE DUE THE PRESENCE OF WEDGE FILTERS

摘要

The theoretical determination of wedge factor and the spinning angle of isodose plane given by the introducing of the wedge in the beam and the practical verification through measurements performing at the Co-60 radiotherapy unit from Radiotherapy Department from the "Sf. Ap. Andrei", Emergency Clinical Hospital Galati. The wedge filters raise two problems in the radiotherapy practice: progressive attenuation of beam across the field (the thinner side of the wedge attenuates the beam less than the thicker side) and spinning of isodoses curves plate. In our study we tried to find the concordance between the different values of wedge factor (W_f) calculated after measurements at the radiotherapy Co-60 unit, with theoretical values of W_f calculated from formulas and given in Theraplan Planning System Charts. Our results are encouraging because we observed that the values are in very good concordance with not statistically significant differences between the two data sets. Also we calculated he spinning angle of isodose plate conform a theoretical relation and compared with the data from Theraplan Planning System Charts. The concordance between the theoretical and the experimental values was very good.