The patient equivalence of the RANDO phantom for cobalt gamma rays.

Abstract

The RANDO2 “average man” or “average woman” phantoms are especially designed for use in connection with radiation dosimetry studies. The construction of the phantom, which has been discussed in detail in the literature (1, 2), consists of a special thermosetting synthetic rubber which is molded around a natural human skeleton. Lungs are simulated with a special foam reported to have a density of 0.32. During the past three years a RANDO “average man” phantom has been in use at Walter Reed General Hospital in the development of a number of special dosimetry technics using 60Co gamma rays and 2 MVp x rays. In all of these studies the exposure in the phantom was measured with film or miniature ionization chambers. In the application of the measurements to treatment planning we have assumed that the phantom was “patient equivalent,” i.e., that an exposure at a depth and in any particular anatomical site in the phantom would accurately predict the exposure under similar conditions in the patient. This assumpti...