The principles and practice of brachytherapy are explained in this detailed book. Brachytherapy is a radio therapy commonly used as an effective treatment for cancer. The treatment involves the appropriate arrangement and selection of radiations which varies depending on the expertise of the physician. This book describes how brachytherapy can vastly contribute in the field of radiation oncology. This book discusses specific yet important topics such as progress in Californium-252 neutron, issues related to dosimetric method, iodine-125 production, clinical aspects of brachytherapy etc. This book will be a useful read for readers including radiation oncologists, students, professionals in other medical fields and even patients.