Technical Methods in Radium Therapy 235 



radium. But no amount of ingenuity in itself can make any 

 headway in treatment unless it is embodied in an instrument or 

 in a process which convinces the therapist of its undoubted 

 utility and safety. 



External Irradiation 



The range of this method varies from the application of a few 

 milligrams in the form of a capsule, to the use of 10 grams at a 

 time. At the present time, considerable diversity of opinion 

 exists about the utility of these gram units (the use of the de- 

 plorable term "bomb" for these units is happily declining ) . What 

 need is there for mounting 5 or 10 grams of radium into a single 

 unit as a gamma-ray source when this type of radiation can so 

 nearly be duplicated by X-rays? The argument may, how^ever, 

 be presented with equal logic the other way round ; w^hy go to 

 the trouble of installing complicated and expensive apparatus 

 which will almost certainly have to be discarded after 10 years' 

 service, when one can have a most useful source of radiation 

 requiring little apparatus and a minimum of servicing by a 

 staff of engineers, a source, moreover, that shows an inappre- 

 ciable decline over the same period of time ? 



As a matter of fact, there are very good reasons why one 

 source does not exclude the other. It is true that the quantitative 

 yield of penetrating X-rays from a modern tube at a quarter 

 of a million volts far exceeds that from a 10-gram radium unit 

 (perhaps 10 times as big), but the latter has many advantages. 

 It is often easier to apply to the patient, it is especially suitable 

 when repeated and prolonged treatments are needed, and its 

 servicing is so effective that one can almost say that these units 

 do not suffer from breakdowns. "So it may reasonably be ex- 

 pected that these units, ranging from 1 to 10 grams of radium, 

 will be more and more used, provided that the present downward 

 trend in the cost of radium continues. 



Intracavitary Irradiation 



The introduction of radium (and radon) into the natural 

 cavities of the body when they are the seat of disease has been 



