History and perspectives

The use of hyperbaric oxygen or bromodeoxyuridine for radiosensitization of tumors has failed to obtain full support by radiotherapists; therefore considerable attention has been directed to high-LET radiations such as fast neutrons and π mesons. The high-LET radiations introduced for their lower (oxygen enhancement ratio) have other beneficial features for tumor therapy, that is, low repair and low age dependencies. Encouraged by success with high-LET radiations, scientists have extensively studied the modification of cellular radiosensitivity by chemical (sensitizers) as well as physical (hyperthermia) means. These new modalities are experimentally effective for sensitizing tumor cells, not only in case of ionizing radiation but also with some antitumor drugs. The development of and prospects for these new aspects of cancer treatment are discussed in this book