Comparison of optimised treatment plans for radiosurgery and conformal radiotherapy

The aim of conformal radiation therapy and of radiosurgery (Gamma Knife and Multi-beam radiosurgery) is to irradiate the pathological target volume with ionising radiation while avoiding as well as possible the surrounding normal tissues. Considering the accuracy of these treatments, it is interesting to compare the different techniques to evaluate their effectiveness. This comparison involves 8 clinical cases. For each treatment modality, we compare indexes defined in the international literature by the Radiation Therapy Oncology Group (RTOG). This theoretical study shows (i) the interest of the use of intensity modulation in the case of conformal radiation therapy and (ii) the improvement of RTOG indexes with using the conformal radiotherapy although the VNT25% and the VNT50% remains better with the radiosurgery.