Distribution of Skin Doses Over Scalp in Therapy of Tinea Capitis With Superficial X-Rays

THE DEPILATORY effect of superficial x-rays is curative in almost all cases of epidemic tinea capitis due to Microsporum audouini. In this country the Adamson-Kienböck method of administering the radiation has achieved widespread usage. The radiation is delivered over five unshielded focal points which are approximately 5 in. (13 cm.) apart. Earlier investigators have noted that it is not possible to achieve a uniform dosage when irradiating a spheroid object such as the scalp. In the Adamson-Kienböck technique, a considerable degree of overlapping occurs in the regions between the focal points. For this reason there is a significant disparity in dose between the radiation received at the focal points and in the areas of greatest overlap. The use of this method would involve a decided risk if the quantity of radiation absorbed in the areas of overlapping could be shown to approximate the dose required for permanent