Radiation therapy for malignant melanoma.

Sufficient biologic and clinical evidence now exists to refute the longstanding dogma that melanomas are uniformly radiation resistant and hence radiation therapy has little role in the management of this disease. Although surgery remains the treatment of choice for the vast majority of localized melanomas, available data indicate that radiation therapy is a viable alternative for a few subsets of patients in whom surgery would result in cosmetic or functional deformity, such as patients with large facial lentigo maligna melanomas or small or intermediate-sized uveal melanomas. Retrospective and Phase II prospective studies have revealed that elective/adjunctive radiation therapy improves the local-regional control rate in patients with thick primary lesions, nodal involvement, or mucosal melanomas. However, the impact of elective/adjunctive radiation therapy on the survival rate has yet to be determined. Radiation therapy has been established as a simple and cost-effective treatment modality for palliation of patients with symptomatic metastatic spread. The response of metastatic deposits to radiation varies with the tumor volume, total dose, and dose per fraction. The choice of optimal fractionation depends on tumor site and the patient's survival expectation. New data indicate that hyperthermia enhances the response of metastatic lesions to radiation. Ongoing research with a variety of experimental strategies may offer the possibility of further increasing the utility of radiation therapy in the management of this disease.