Energy absorption in radium therapy.

The paper describes the calculation of the energy absorption or integral dose in a model “patient”, composed of cylinders and elliptical cylinders, from a point source of radium. Calculations have been made for about 800 positions of the source in and near the body. From these results the integral dose, in gm.r/mg.hr., received during intracavitary, interstitial, and superficial radium therapy, may be obtained, (1) in the case of deeply placed radium from a central axis curve, (2) for radium placed near the surface of the trunk from a table. Figures are also given for some superficial points in the head and neck. A table is given of the energy absorption in cylinders of tissue with a point source at the end of the axis, and consideration given to the subject of integral dose in hollow cylinders, containing a core of air.