POWERFUL RAY

New Zealand Herald, Volume LXXIV, Issue 22618, 5 January 1937, Page 6

POWERFUL RAY

TREATING CANCER INSTALLATION IN LONDON [from our own correspondent] LONDON", Dec. 12 The new M osteite Sassoon X-ray Therapy Department at St. Bartholomew's Hospital, which was' Opened this week, is unique, it is the finest installation of its kind in the world. It is "built round" the great X-ray tube, .'SO feet long and weighing 10 tons, which is designed to produce a beam of greater penetrative power, higher intensity and shorter mean wave-length than has yet been used for the treatment of cancer, it will operate at any ' voltage from 2-50,(XX) to 1,000.000, the highest constant voltage ever employed for healing purposes. The X-ray chamber, through which the middle part of the tube passes horizontally. is equipped with a movable floor which can be raised and lowered by pressing a button, so that the range of the beam may be varied widely. The couch upon which the patient lies makes possible a great range of smaller adjustments. A microphone stands by the couch so that the patient may talk to the nurse or doctor outside the chamber. It is impossible for a doctor safely to keep the patient under direct observation during treatment, but this difficulty lias been solved by an ingenious arrangement of eisrht curved mirrors. They pass a reflection through a small aperture, heavily protected, in the top corner of the chamber, down to the observer's desk. The safety position is automatically assumed by the apparatus whenever a door of the chamber is opened. Further precautions for the protection of the operating personnel appear in the composition of the walls of the chamber and generating rooms, which are built of interlocking blocks of barium concrete. The doors of the chamber are of heavy steel plates, designed to prevent radiation leakage. No therapeutic X-rav tube of aa equal efficiency exists in the world today. There are only three or four tubes which can work with over 500,000 volts, and, in the British Umpire, the next most powerful is that at the Cancer Hospital, in Fulhain Road, which can work up to 400,000 volts. In America, at Pasadena, a tube exists which has been operated with 1.200.000 volts, but with a fluctuating potential. It cannot sustain 1.000,000 volts, and in any case it is chiefly used for physical research. The St. Bartholomew's Hospital in* stallation can provide a range of radiation which includes all but the very highest of the gamma rays of radium, and an unofficial simulation puts its intensity on an equality with that which would be produced by far more radium than can at the moment be assembled in one bomb. It is certain that the tube will achieve a much greater effi* cieney for healing purposes in all cases of deep-seated cancer; but for this it must be "run-in" like a new car. Pertiaps of greater ultimate importance are the facilities it will give for acquiring new knowledge, by investijl®" tion and research. But no speedy discovery is to tie expected from its use, and it will probably be five years at least before its full value can be au» uounced to the world.