Superficial “;Burns”; of Skin and Eyes from Scattered Cathode Rays

Abstract

The present report is concerned with varying degrees of injury received by six men in the Department of Radiology at the Massachusetts General Hospital as a result of a few seconds' exposure to scattered electrons from a 1,200-kv. electrostatic generator. The main purpose in presenting this report is to prevent a repetition of that experience. It seems important also to emphasize the dangers inherent in scattered as well as in direct cathode rays, in order that the recurrent enthusiasm for their therapeutic possibilities may not be permitted to overshadow their possible harmful effects. Reports of serious radiation injury to persons working with roentgen-ray generators are uncommon at the present time, although in the early days of roentgenology such reports were common. Those trained in the use of the roentgen ray have a definite respect for its latent injurious effects, and it is to be noted that relatively few radiation injuries are seen in this group. Most of the injuries which have occurred have been due to lack of training. In retrospect, therefore, the question arose as to whether an accident such as occurred in this hospital is excusable, whether all the possible dangers associated with cathode rays should have been appreciated by at least the senior members of the group. The effect of exposure to cathode rays in the direct beam was of course known (9, 10), but the effect of scattered cathode rays was not understood. The scattering was thought to be similar to the fluorescence of ionized air which is visible beneath the cathode ray port in a dark room (Fig. 1). Subsequent careful review of the medical literature has failed to reveal any reports of injuries due to scattered cathode rays. Numerous articles have dealt with the physical and the biologic aspects of these rays, a few with their use in the treatment of certain skin diseases, but only a rare publication has mentioned accidental injury due to them. Jacobsen and Waddell (7) found that the effects of cathode rays on the skin of the rat were similar to those of roentgen rays, and that actually the effect of the roentgen rays was due to cathode rays which originated in the tissues. Jacobsen (6) later confirmed these observations by experiments on the skin and testis of the white rat. Brasch (2) reported experiments on white mice and rabbits made in the direct beam with cathode rays generated at 2,500 kv., 1 ma., at 100 cm. distance. The mice died a few days after exposures of 1/10,000 to 1/1,000,000 second. These observations indicate that the effects of cathode and roentgen rays are similar, except that the former have a definite and limited depth of penetration without underlying reaction. Wilhelmy (11), using cathode rays energized at approximately 210 kv., 1 ma., and a treatment distance of 5 cm., was able to produce an erythema with 1/2 second exposure.