Possibility of Using Thulium 170 as a Teleradiographic Source for Localization Purposes in Teletherapy with Cobalt 60

Abstract

Thulium 170 has been used as a radiographic source by Mayneord for internal radiography and for radiography of the extremities, and teleradiographic units using thulium 170 have been developed by the Argonne National Laboratory. In general, radiographs thus obtained are likely to be inferior in quality to those produced by standard equipment, and consequently thulium 170 might be expected to have few uses in a hospital. There is at least one phase of therapy, however, in which an isotope source may be valuable, i.e., for localization purposes in teletherapy with cobalt 60. One of the outstanding problems in the practical use of cobalt 60 teletherapy is the difficulty of obtaining good localization films because of lack of contrast between bone and soft tissue. Portable radiographic units can be employed for the purpose, but the difficulty of duplicating the set-up does not encourage their use and it is more common practice to depend upon the poorer quality cobalt-60 films. The use of a highly active teler...