ROENTGEN RAYS AGAINST CANCER—TRUMP 
pital in Boston began the first constant- 
potential X-ray treatments with the 
M. I. T. air-insulated electrostatic 
generator operating at slightly more 
than 1 million volts. This was 
followed by the Massachusetts General 
Hospital program in 1940, under Dr. 
George W. Holmes and now Dr. 
Laurence L. Robbins, using M. I. T.’s 
1-million-volt pressure-insulated gen- 
erator. At the St. Bartholomew’s 
Hospital in London clinical treatments 
were begun by Dr. Ralph Phillips in 
1937 at 700 kilovolts and the large 
transformer-rectifier apparatus was 
gradually improved to million-volt 
operation. he Memorial Hospital in 
New York has used General Electric’s 
million-volt resonance transformer for 
X-ray therapy for about 10 years. In 
Norway, Dr. S. N. Bakke of the 
Municipal Hospital, Haukeland, Ber- 
gen, began treatments in 1942 with a 
1%-million-volt air-insulated electro- 
static generator designed by Odd 
Dahl, formerly of the Carnegie Institu- 
tion of Washington. A number of 
other programs at intermediate volt- 
ages could be mentioned. All have 
reported with varying degrees of 
enthusiasm the observation that cer- 
tain more favorable therapeutic re- 
actions could definitely be ascribed to 
the higher voltages at which the 
X-rays were generated. 
Radiation Therapy at 2 and 3 
Mullion Volts 
Since January 1946, in a clinical 
therapy program under the medical 
direction of Dr. Richard Dresser, 
patients have been treated on the 
grounds of M. I. T. with roentgen 
radiation produced by an electrostatic 
research generator which can operate 
at well over 3 million volts. In the 
ensuing 18 months, complete treat- 
ment series were given to more than 
150 selected patients. After interrup- 
tion during the summer of 1947 this 
clinical program will be resumed with 
a larger clinic and improved, higher- 
voltage apparatus. Roentgen radi- 
ation produced by 3 million volts 
211 
exceeds in quality the gamma rays 
from radium in equilibrium with its 
decay products. The output intensity 
of this therapeutic generator is several 
times greater than the combined 
radiation output of the entire world 
supply of this precious material. This 
roentgen-ray source operates at the 
highest voltages thus far clinically used 
in cancer therapy. The preliminary 
observations made in the course of the 
work have generally confirmed the 
physical evidence that roentgen rays of 
several million volts of energy are 
superior in certain important respects 
to the relatively low-energy radiation 
now in common use and even con- 
siderably better than the 1-million-volt 
radiation investigated over the last 
decade. ‘That extensive clinical re- 
search by many investigators will be 
required to exploit fully the thera- 
peutic qualities of these high-energy 
radiations is also evident; several years 
of physical and clinical research will 
be needed to consolidate the benefits 
derived from higher voltages. 
The supervoltage X-ray source lo- 
cated in a small building on Institute 
property near Vassar Street in Cam- 
bridge is a pressure-insulated electro- 
static generator of the type first 
developed by Robert J. Van de 
Graaff. Designed by the electrical 
engineering group in 1940 for physical 
and medical research, it was applied 
during World War II to the irradiation 
of atomic-pile materials with intense 
ionizing radiations and also served as 
a prototype for the electrostatic gener- 
ators’ developed “ate Mey Fxrtor 
military radiography. Now, reapplied 
to peaceful pursuits, high priority is 
given to the daily medical program, 
but the unusual quality and quantity 
of ionizing radiation produced by this 
equipment is also of interest in other 
investigations. In a cooperative study 
with the Department of Food Tech- 
nology, the biological and _ photo- 
chemical effects of both X-rays and 
cathode rays on micro-organisms and 
on food and drug products are being 
studied. In another aspect of this 
