154 Prevention o£ Deafness 



ing the central beam of the rays from the various portals in the neck so that 

 they will cross or converge at the exact spot where they are needed; the time 

 consumed and the expense of the treatments, which must be divided over a 

 period of two or three weeks; a large percentage of the rays is absorbed by 

 skin and muscle, and never reaches the nasopharynx; therefore the total 

 irradiation used is much greater than the amount necessary to reduce the size 

 of adenoids. It is not wise unnecessarily to irradiate the base of the skull and 

 centers of ossification to this extent in a growing child, especially since the 

 series of treatments may have to be repeated several times to maintain the 

 patency of the tubes. The chief objection is the inaccuracy of this method in 

 young children. On the other hand, radon can be compressed and an amount 

 equivalent to a gram of radium salts may be sealed in a capillary glass bulb, 

 placed in an applicator small enough to pass along the floor of the nose 

 without anaesthesia and without pain, and brought into direct contact with 

 the tissue to be treated. The applicator remains in place from three to five 

 minutes, depending on the number of millicuries it contains. The effect of 

 the treatments is determined by direct inspection with a nasopharyngoscope 

 and by audiometer tests. When necessary the treatments are repeated at inter- 

 vals of a month, but rarely more than three or four are required. We have 

 often irradiated from fifteen to tw^enty school children in an afternoon. Many 

 children have been followed for a decade or more and we are confident that 

 no untoward local or systemic effects occur. Partially occluded Eustachian 

 tubes set in train a series of physical changes in the membranes of the middle 

 ear and mastoid cells that eventually impede the movements of the ossicles. 

 The earlier the condition is recognized and treated the better the results. For 

 this reason children over fifteen and adults are rarely benefited. 



Irradiation does not cure any and every type of deafness. Its purpose is to 

 remove lymphoid tissue from locations that will cause deafness. Detailed 

 results of a study of 1,365 school children have been published and need not 

 be recounted here. It is a type of experiment that requires years for its com- 

 pletion, and further reports will appear from time to time. The method is 

 safe and inexpensive and if applied in schools would in time greatly reduce 

 the recent estimate of three million children with seriously impaired hearing. 



