Embracing the transformation of radiation sciences by the recent surge of developments in molecular biology, this graduate-level textbook offers an up-to-date analysis of in vitro and in vivo molecular responses in the body induced by ionizing radiation. With a unique emphasis on medical physics applications, "Biomolecular Action of Ionizing Radiation" also presents a much needed, in-depth perspective on clinical applications for the treatment of cancer and radiation injuries. Based on a popular course given by the author at McGill University, the book places the traditional tenets of radiation biology in the context of contemporary cell and molecular biology.Using terms that non-experts in molecular biology can understand, it clarifies the underlying mechanisms of radiation effects on molecular interactions including signal transduction pathways, modes of cell killing, and non-targeted effects. The author subsequently associates key principles and advances with potential applications, including the use of ionizing radiation as a cytotoxic and cytostatic agent, and radiosensitization by targeting molecular intermediates or signaling molecules involved in radiation-induced processes. Raising the standard for radiation biology textbooks that are currently available, "Biomolecular Action of Ionizing Radiation" is an outstanding resource for advanced undergraduate and graduate students in medical physics, radiation oncology, radiation biology, and those who have an interest in the radiation sciences and in cancer treatment.