Özet:

The aim of our study is to control the dozimetric process used in the in-vivo dozimetry dosage calculation algorithm, compared to the data obtained from the three-dimensional computer treatment planning system (BTPS) of target volume and critical organ doses obtained by the source-skin distance (SSD-Source Skin Distance) method. With a computer tomography simulator with a range of 0.5 cm of tomography cuts, target volumes and critical organs were conturred on the randofantom. Calibrated thermoluminescence dosimetry (TLD) chips were placed at the points specified on the randofantom. The average measurement values were obtained by radiation 5 times for each technique. The target volume and critical organs doses were studied. Values below ±5% between BTPS and measureed values were taken within acceptable limits. The average dose values calculated by BTPS at three points within the target volume with the three and four field SSD technology are 206.67 cGy and 209.03 cGy respectively, and the average doses measured by TLD chips at these points are 208.55 cGy and 210.78 cGy respectively. In both techniques, the difference between the doses measured and calculated in the heart and lungs points was less than 5%, while the difference in the right breast skin was up to 14%. The objective of breast radiotherapy is to reduce the possibility of recurrence and to minimise the radiation of solid tissues by providing homogeneous dosage distribution in the target volume. The results obtained in our study show that dosage measurements with TLD may be beneficial in the determination of errors that may occur in the treatment planning process, although they are not ideal.

Anahtar Kelimeler: