Radiation therapy as primary and adjuvant treatment for local and regional melanoma.

BACKGROUND: The role of radiation therapy as primary and adjuvant therapy for localized or locally advanced melanoma is controversial.
METHODS: To develop evidence-based guidelines, PubMed was searched using the keywords melanoma AND (radiation OR radiotherapy). These references were reviewed and the relevant articles selected. The articles were then reviewed for further references. Because of the paucity of prospective or randomized trials, no attempt was made to classify the quality of the results.
RESULTS: No phase III trials of nodal irradiation for prevention of regional recurrence are available. A phase III trial is being completed by the Tasman Radiation Oncology Group. A phase II trial has been completed by the group. Multiple retrospective series have been published. The available data appear to confirm that nodal radiation therapy is effective in preventing nodal recurrence. No dose response or fraction size response was found. According to generally accepted guidelines, radiation therapy should be offered for patients who have nodes greater than 3 cm, more than 3 involved nodes, or extracapsular extension. For radiation therapy for the treatment of metastatic disease, a phase III trial showed that 50 Gy in 2.5-Gy fractions was as effective as 32 Gy in 8-Gy fractions, with 25% complete remission and 35% partial remission. In contrast, the retrospective studies support that larger fraction sizes, at least 4 Gy, are more effective.
CONCLUSIONS: Adjuvant nodal irradiation appears to be effective for the prevention of nodal recurrence. Radiation therapy can also be effective for treatment of local disease, if surgery is not an option.