This book provides a complete reference on the physics and techniques of stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT). It also details procedures used in neurosurgery and radiation oncology. The book covers the technological advancements in stereotactic radiosurgery and radiation therapy, dosimetry requirements, treatment planning techniques, and quality assurance methods. Unlike other books, this book starts from the basics and explains each step in SRS, SRT, and SBRT. Each chapter contains a short summary emphasizing the chapter's salient features.