Color Isodose Curve Plotter Applied to Beam Focus Radiography

Abstract

An apparatus was constructed to facilitate superimposition of the beam focus radiogram upon the axial transverse tomogram, in order to guide subsequent radiation therapy more accurately. The apparatus automatically draws six isodose curves in three colors, by plotting the relative doses of the beam focus radiogram. In addition, the isodose chart was made at the same magnification as that of the axial transverse tomogram. A satisfactory and reliable technique was achieved. The accuracy and the reproducibility of the apparatus was good. Clinical application of this method to a case of hypophyseal tumor is described.