The Status of Insurance Restitution for Holocaust Victims and Their Heirs: Hearing Before the Committee on Government Reform

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1917 edition. Excerpt: ...lesion when not more than 20x could be safely put through one particular surface area. Pfahler uses from 4 to 40 surface areas and passes a full dose through each, making a total of from 80 to 800 units. To produce any marked effect.upon the deeper tissues it is nec essary to use screens or filters to check the less penetrating rays which would otherwise be absorbed by the superficial tissues and cause marked destructive changes there before the less numerous and more penetrating rays could act on the deeper tissues. In order to obtain the most penetrating x-rays for this method of so-called deep Roentgen therapy, the well known Tiefenroentgentherapie of the Germans, it is necessary to employ a hard tube of high degree of vacuum and an electrical apparatus of high voltage. The rays are not all of equal penetrability and it has been found that they are more homogeneous when the softer have been filtered out by an aluminum screen 8 millimeters in thickness. Certain roentgenologists also use a heavy piece of leather. Radium. When radium is used for the treatment, screens or filters of lead 2 to 3 millimeters in thickness, of brass 1.2 millmeters or other heavy metals such as silver, gold or platinum, allow the penetrating hard beta and gamma rays to pass and intercept the alpha and soft beta rays which would otherwise be absorbed and cause destructive changes in the superficial tissues. As the amount of the more Penetrating rays-is only a small portion of the total activity, less than 5%, it is nec essary in deep therapy to make exposures correspondingly long. The principles of cross fire as well as deep therapy are made use of in the treatment of leukemia by surface applications of radium. The...