This monograph discusses all forms of therapy in which either the source or the target of the ionizing radiation is kept in motion during the treatment. The text is detailed, explicit, and clear. There is a wealth of well-reproduced photographs of apparatus to illustrate techniques, and the mathematical diagrams are drawn with exquisite precision. The bibliography fulfills the promise made in the preface of a complete coverage of existing literature, including very recent American and Scandinavian contributions. The book should be seen by every roentgenologist.