This book provides a comprehensive insight into this special form of image-guided interventional therapy and its indications. It begins by introducing the fundamental principles of radiotherapy, the most up-to-date guidelines and the interdisciplinary aspects of the technique and then expands to more practical aspects such as therapy planning, indications and the use of the technique for certain tumor types, including liver metastases, rare tumors, cerebral malignancies and prostate tumors. Written and edited by pioneers in this technique, the chapter’s outline results and numerous illustrated case studies from the daily routine of daily clinical practice providing an insightful guidance to this relatively new but growing method. This is an indispensable guide for oncologists, radiation therapists and radiologists, but also general practitioners and all other specialties, which have an oncological focus.