From the May 20, 1933, issue

LARGEST X-RAY TUBE BEGINS TO BATTLE AGAINST CANCER

The mightiest weapon yet to enter the war against cancer was put in operation at the Mercy Hospital Institute of Radiation Therapy of Chicago. It is a new, 800,000-volt X-ray tube that, operating on a current of 1/100 of an ampere, is estimated to emit radiation equal in quantity to that from $75,000,000 worth of radium.