The book will cover all the relevant theranostics aspects involving pairs of radiopharmaceuticals used in imaging and therapy for cancer treatment: historical perspective; cancer biology and radiation biology models; clinical applications; radionuclide production and radiopharmaceutical preparation; source calibration and imaging instrumentation; biokinetic modelling and dosimetric formalisms; epidemiological studies and clinical trials; radiation safety considerations; regulatory requirements; staff education, training and competences; economic projections, and future outlook. It is planned to keep the chapters at a medium academic level. At this time, radiotheranostics information is dispersed in books, journals, congress proceedings and organizations’ websites. Compiling and organizing the material should give medical and health physicists not just the necessary tools to estimate and document the individual dosimetry of patients undergoing radiotheranostics treatment, but will also empower them to • convince the cancer community that such a dosimetry improves cancer control and results in longer survival times and • influence national policy makers to require organ dose estimates/calculations. The book is aimed at academic and practicing clinical medical and health physicists with basic knowledge of nuclear medicine. Although the book is not meant as a textbook, medical physicists in nuclear medicine physics training may also find the book useful.