[Indications for and results of percutaneous radiotherapy of malignant melanoma].

Malignant melanomas may develop from naevoblasts by way of the junctional naevus; from melanoblasts by way of melanocytes or by way of melanosis circumscripta praeblastomatosa. It is reasonably certain that there is no direct malignant degeneration of a naevus-cell-naevus as a result of acute or chronic irritation, but most authors reject sample excision nevertheless. Malignant melanomas from naevoblasts are relatively insensitive to radiation and dangerous, whereas those developing from melanoblasts are relatively sensitive to radiation and grow slowly. Melanomas which have developed on an unchanged skin are critical because they metastasize fast and take a rapid course. 29% of 237 stage-I patients out of a total of 680 developed metastases during the first year following surgery and irradiation, and 14% after 2-9 years. Radical removal of lymph nodes results in congestion combined with oedema, and involves the risk of melanoma cells being carried into the perilymphatic tissue. Early irradiation of regions involving metastatic risk seems to be preferable over idssection of lymph nodes. Experience has shown that surgery preceded and followed by radiotherapy, and additional surgical or radiological treatment of regional lymph-nodes should be recommended at this time. Evidence concerning the effects of endolymphatic, cytostatic, and immunotherapy is as yet incomplete. The five-year survival rate in state I is said to be 71% following surgery, up to 80% following irradiation and subsequent surgery, up to 78% following surgery and subsequent radiotherapy, and up to 72% following radiotherapy alone. Survival rates are about 14% higher following surgery and electron irradiation.