COMPARING THE RADIOTHERAPY PLANNING USING COMPUTERIZED TOMOGRAPHY SLICES WITH THE RELEVANT SET-UP POSITIONS IN BREAST CANCER

In this study, we investigated, the use of computerized tomography in the treatment planning of breast or chest wall tangential fields and to compare them with the relevant set-up positions. The differences were marked and the changes at the percentages of irradiated lung volumes were studied. The contours of the chest wall or breast of 9 patients included in this trial were taken at the lung volumes were determined by ultrasonography and computerized tomography, respectively. As a result, it was determined that, the height of the treatment fields and the beam entrance points of the lateral tangential beams showed 2.2±1.2 and 2.6±0.9 cm alterations, respectively. Thus the lung proportions in the treatment volumes were underestimated in the average of %61.84±25.8 in the treatment plans performed with CT slices alone.