RESUMEN
Developments in radiotherapy treatment techniques provide new options and treatment opportunities for patients. One of these is the Extra-cranial Stereotactic Radiation Oncology and Nuclear Medicine [NEMROCK]. Several clinical cases have shown that a radiotherapy treatment allows delivery of high total doses to the tumor. However, damage to healthy tissues as side effects caused from excess radiation, is a factor to be considered. Extra-cranial Stereotactic Radiotherapy, with its precise tumor definition, exact patient localization, and immobilization can reduce the damage of healthy tissues surrounding the tumor, while still allowing higher total doses to be delivered to the planning target volume [PTV]. In this study, development of Brain Lab cranial software system is achieved to be applicable for the Extra-cranial lesions using the circular collimators are-based radiosurgery. By this technique a good dosimetric results were obtained, with minimum doses delivered to health tissues and maximum target dose. The best of treatment is based on dose distribution, conformity index, and dose volume histograms for the patient