Effects of patient positioning and of thickness variations on radiotherapy

Correct patient positioning is essential for good aiming in radiotherapy. This can be achieved using back and side pointers, but sometimes these devices are not being used in order to simplify and make the positioning faster. The effects of such a simplification have been studied and measured. The results of this experimental study show that in thicker patients (over 24 cm) the use of back and side pointers is of great importance, because the variation of the patient thickness and angulation can significantly influence the aiming angles and dose percentages.