PRESENT TRENDS IN CANCER-THERAPY WITH HIG H-LET RADIATIONS

Application of high-LET radiations in cancer therapy is based on radio biological arguments : great efficiency against hypoxic cancer cells, or cells in resistant phases of the mitotic cycle or quiescent. Howeve r, from a clinical point of view, the problem of the selection of pati ents who could benefit from high-LET radiations is not solved. Clinica l observation shows that high-LET radiations bring a benefit for certa in types of rumours : salivary glands, antrum, prostate, sarcomas, etc . These rumours are, in general, slowly growing, well differentiated a nd resistant to conventional x-rays as well as chemotherapy. Among hig h-LET radiations, fast neutrons have been most widely used. Today, neu trons can be applied in technical conditions, and with a allow the rad iotherapist to apply high-LET radiations with an excellent physical se lectivity. Unfortunately, the complexity of the equipment and mainly t he cost prevented the development of the technique.