Results of treating malignant melanoma intralymphatically with radioactive isotopes

Endolymphatically administered 131I-Ethiodol delivers sufficient irradiation to the lymph nodes in human beings to destroy microscopic deposits of melanomatous cells lodged within the nodes. The primary melanoma is treated by orthodox surgical techniques. Patients classified as having clinical Stage I melanoma receive no additional surgical intervention but receive 131I or 32P endolymphatically and are, thus, spared the trauma of a radical axillary or groin dissection and their ensuing complications. A five year survival rate without evidence of residual or recurrent melanoma by 18 of the 22 patients observed five years or longer is encouraging. Patients with Stage II melanoma are treated endolymphatically by a combination of isotopes and surgical removal of the primary melanoma and the lymph nodes. The penetration of the irradiation from the administered isotope is not sufficient to destroy the cancer. In such instances, irradiation of lymph nodes outside the operative field, irradiation of any nodes inadvertently left behind, and irradiation to cancer cells within the lymphatic vessels offer an additional dimension in the treatment of these patients. A five year survival rate of 28.5 percent in a small group of patients is better than that obtained with surgical excision alone. (U.S.)