Computers have had and will continue to have a tremendous impact on professional activity in almost all areas. This applies to radiological medicine and in particular to radiation therapy. This book compiles the most recent developments and results of the application of computers and computer science as presented at the XIIIth International Conference on the Use of Computers in Radiation Therapy in Heidelberg, Germany. The text of both oral presentations and posters is included. The book is intended for computer sientists, medical physicists, engineers and physicians in the field of radiation therapy and provides a comprehensive survey of the entire field.