Stereotactic Radiosurgery; Measurements, QA and Dose Optimization

The aim of this study is to have get accurate calculation of three dimensional dose distributions inside and outside the target volume, calculation of dose volume histograms (DVHs) for the target and specific sensitive organs and obtain dose distributions which conform to target shapes and give a sharp dose fall-off outside the target volume. Stereotaxy term means application of the form of treatment through good fixation of the patient whereas applied directly to the lesion without operation, relied mainly on the external landmark at the patient external surface.Moreover, accurate positional and numerical delivery of dose to the predetermined target, dose delivery accomplished in a reasonable amount of time to get low skin dose to avoid epilation, low eye lens dose to avoid cataract formation and low or negligible scatter and leakage dose to radiosensitive organs to avoid subsequent somatic and genetic effects of radiation.