The various steps in our knowledge of the physical and chemical properties of radium which have led to its use in the treatment of cancer, and the successive improvements in its mode of application are of much interest; but since they are not essential to the present purpose, detailed reference to them may be omitted. For the therapeutist the most important question concerning radium today is not how many cases of cancer this agent has cured, but whether it has in any sense a specific action on tumor tissue.
On cellular tumor tissue the action of radium is selective and specific, in the sense that tumor tissues are from four to seven times as sensitive as most normal tissues. Without notable inflammation of the skin, without extensive necrosis of tumor tissue, and without destruction of the normal elements involved, tumor cells may be made to disappear, and the tissue returns
EWING J. RADIUM THERAPY IN CANCER. JAMA. 1917;LXVIII(17):1238-1247. doi:10.1001/jama.1917.04270040226010