This book is the result of research on Radiosurgery and Radiotherapy systems such as CyberKnife and TomoTherapy,and including a brief description of the Cancer, basic of Linear Accelerators (LINAC) and function principles of conventional and modern radiation therapy systems. It can be useful for all enthusiasts and staff in CyberKnife and Radiation oncology centers, as well as for patients who are candidates for radiation therapy especially with cyberknife system.