Degenerative Effects of Large Doses of Roentgen Rays on the Human Brain

In 1936, one of us with the late Dr. Adolph Hartung (62) reported preliminary observations on 15 cases of brain tumor of various types, from the service of Dr. Eric Oldberg, treated with a total dose (air) of 15,000 r of high-voltage roentgen rays. Our first impressions were favorable, since occasional results were noted that had previously been unobtainable. In the twenty months from the beginning of the study until the time of the first report, no untoward effects were seen. Similar treatment has been given to selected cases since that time. Only recently have we had the opportunity of examining postmortem cases showing degenerative changes as the result of such therapy, although the literature has, from time to time, contained reports of damage from similar doses. With the development of the fractional protracted technic of radiation therapy, after the pattern of Coutard, much larger doses of radiation were delivered to neoplasms throughout the body, including those of the central nervous system, than were used previously. The fractionated technic was particularly welcome for intracranial lesions, especially in those clinics where aggressive radiotherapists did not have adequate neurosurgical support and tumor cases were treated without the benefit of preliminary decompression. Review of Literature The early reports of radiotherapy of intracranial growths showed the high mortality rate of 16.9 per cent (61) directly traceable to the irradiation. Less severe sequelae were common. Béclère (6) ascribed these untoward results to what he called the “prereaction,” an acute hyperemia and swelling of the irradiated area, appearing from one to several hours after treatment and disappearing in from twenty-four to forty-eight hours. Froment, Delore, and Tassitch (32) measured the cerebrospinal fluid pressures both before and after treatment in five cases. They found increased values following irradiation, more pronounced with higher doses and when the pressure was previously high. Such developments could easily be fatal to a patient already in critical condition. The use of the fractional protracted technic, with a small initial dose which is increased by small daily increments, has reduced the danger of roentgen therapy even in cases without decompression. Thus, Cutler, Sosman, and Vaughan (14) recommended a diagnostic therapeutic test in cases of suspected medulloblastoma prior to operative exploration and felt that, with fractionation and dehydration, serious reactions could be avoided. The tendency to deliver larger doses to intracranial tumors was stimulated by the observations of Bailey, Sosman, and Van Dessel (5) and Sachs, Rubinstein, and Arneson (55). These writers felt that larger doses were desirable, especially in the glioblastoma multiforme group, and that patients receiving such doses as a rule survived longer.