CANCER was recognized clinically many centuries ago, and from earliest times the only known cure has been total eradication of the disease. Anything less spelled failure. Until comparatively recent years surgical methods were the only means by which the destruction of the malignant disease was possible. Soon after the discovery of the X-rays it was noticed that they had a distinctly stimulating action on the skin, causing an erythema, epilation, the formation of blebs, and even of extensive sloughs, according to the quantity of radiation received by the tissues. These observations led to the use of the rays as a therapeutic measure and, among other conditions, to their employment as a destructive agent against superficial cancers. More or less success in this, and the evolution of powerful apparatus supplying more penetrating rays, led ambitious investigators to attempt to destroy, in a similar manner, malignant tissues lying at a considerable distance from the surface. The Germans were particularly active in this development and, in conjunction with a “cross-fire” technic, worked out an elaborate scheme whereby malignant cells of different types, and lying at different depths below the surface, could be given prescribed radiation doses sufficient to kill the malignant cells without actually destroying the overlying normal tissues. This they called the “lethal dose” technic. Again, following the discovery of radium, Curie noted that marked biological effects resulted, when it was left in contact with living tissues, very similar to those produced by X-rays. Destructive effects on deep-lying malignant cells were obtained by burying the radium temporarily, or permanently (emanation), in such tissues, or by using it on the surface by the “cross-fire” technic. Our object in thus restating what is already so well known is simply to call attention to the fact that cancer therapy has, in the past, meant nothing more nor less than destruction. True enough, efforts have been made to induce retrogression of the disease by means of drugs, diets, serums, etc., but these unfortunately have, heretofore, been so unsuccessful as not to warrant further discussion at the present time. Ought we to be satisfied with this campaign of destruction? No indeed, and but few of us are! The more moderate trend of present-day radiation therapy amply proves this. We cannot lessen the destructiveness of surgical methods nor increase their action on the remaining normal body tissues, but with radiation therapy both of these factors are more or less under our control. The aims of roentgenology have, in the past, been to completely destroy malignant cells without injury to the normal tissues. It is now generally recognized that neither of these aims is altogether possible. No matter how heavily radiated, not all cells in a cancer are killed, and it is impossible to destroy cancer cells by heavy radiation without at least seriously affecting the surrounding normal cells.
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