The Miescher technique of x-radiation was employed to treat eight melanotic freckles. Five lesions responded well; the sixth also responded, but an underlying unrecognized malignant melanoma continued to grow, eventually metastasizing. The seventh lesion, repeatedly subjected to electrodesiccation prior to radiation, failed to respond; the eighth recurred three years after treatment.
Modification of grenz-ray machines for the Miescher technique is described. This is accomplished by placing a thin filter of cellulose acetate in the grenz-ray beam to filter out softest radiations.
The Miescher technique is reserved for lesions confined to the dermoepidermal junction, that is, to the precancerous phase. It is not indicated when dermal invasion, ie, malignant melanoma, has supervened.
Further experience and long-term follow-up studies are needed to establish the place of x-radiation in management of this precancer.