Book excerpt: This book is unique in detailing in depth the technological basis of radiation therapy. Compared with the previous edition, all chapters have been rewritten and updated. In addition, new chapters have been included on various topics, including the use of imaging in treatment planning, second malignant neoplasms due to irradiation, and quality assurance in radiation oncology. The book is divided into two sections. The first covers basic concepts in treatment planning and explains the various approaches to radiation therapy. The second part documents the practical clinical applications of these concepts in the treatment of different cancers.