Intensities from Various Radium Packs

It has been known for some time that in order to duplicate dosage for x-ray therapy, the quantity as well as the quality of the beam, in addition to the time factor, must be given, and that the mere statement of milliampere minutes, voltage, distance, and filter is not sufficient for duplication of skin dosage. For depth dosage the additional factors of field size and distance must be given. On the other hand, dosages given in the literature for radium pack treatments list the quantity of radium used in milligrams, the distance of the radium from the skin, the time of application, and occasionally the filtration. From this fact one might conclude that by duplicating these factors with another pack of different construction, the same results might be expected.

At the State Institute, an erythema dose had been established with a 10 cm. pack having a field size of 11 cm. diameter, with emanation as the source of radiation. With the arrival of a large amount of radium element, a four-gram pack, with a field size of 10 × 10 cm., and additional small packs of varying field sizes and radium skin distances of 6, 10, and 15 cm. were designed and constructed to hold radium element either alone or combined with emanation.