Radiation therapy for melanomas of the head and neck

This report reviews experience with radiation therapy in 77 patients with melanoma of the head and neck, a lesion traditionally but incorrectly considered to be radiation-resistant. Thirteen patients with lentigo malignum and 18 patients with lentigo malignum melanoma have been primarily irradiated. In 11 of the 13 patients, the lentigo malignum has been locally controlled with no recurrence from 6 months to 5 years following treatment. One patient had a local recurrence and was salvaged with further radiation therapy, and one patient had residual tumor after irradiation and was salvaged with simple excision. Seventeen of 18 patients primarily irradiated had lentigo malignum melanomas that have been locally controlled from 6 months to 6 years after irradiation. One patient had a local recurrence and was salvaged by excisional surgery. There have been no deaths from lentigenous melanoma, and the cosmetic results of treatment are excellent. We concluded that radiation therapy is a simple, effective out-patient treatment for lentigo maligna and lentigo maligna melanoma. Nonlentigenous melanoma was irradiated after incisional biopsy in 6 patients; local control was obtained in 4 patients although 1 died of distant metastases. Fifteen patients were irradiated after excisional biopsy (margins inadequate); 14 of 15 had local control although 6 died of metastases. Only 2 of 16 patients irradiated for recurrent melanoma were controlled. Analysis of local control versus irradiation fraction size revealed that 17/24 (71%) achieved local control with a dose per fraction of greater than 400 rad as compared with 3 of 12 (25%) in those being irradiated with a dose of less than 400 rad per fraction. We concluded that nonlentigenous melanoma is not radiation resistant and that local excision followed by radiation therapy with a large dose per fraction deserves further study, particularly in melanomas of the head and neck where wide local excision is not possible due to age of the patient or location of the tumor. Nine mucosal melanomas have primarily irradiated and four have been locally controlled.