The proposed book aims to explain the basic principles, concepts and regulations behind radiation protection and their application in the field of radiation oncology practice. This book will be useful to all those students, teachers and practicing professionals involved in the field of radiation oncology namely a) the radiation oncology physicists b) therapy technologists c) radiation oncologists d) oncology nurses and e) regulators undergoing IAEA training in regulations. The main target audience for the book are the medical physics students doing undergraduate or graduate program in radiation oncology physics and the teachers who teach the subject in the academic institutions.