Experimental studies on combined radio-chemotherapy.

A review is presented of the factors which influence dose-response relationships for induction of cell reproductive death in tumours and normal tissues by radiation and chemotherapeutic agents. It is pointed out that inherent differences exist among different types of cells and that environmental conditions of cells are important. A summary is given of the various systems and responses that should be studied experimentally in order to obtain insights in the possibilities to improve cancer treatment by combined radio-chemotherapy. A few examples are discussed of the responses of a rat rhabdomyosarcoma to combined treatments with radiation and vinblastine, which illustrate the importance of cell proliferation kinetics.