Primary malignant melanoma
Radiation treatment does not play a great role in treatment of primary melanomas. In some cases of locally advanced melanoma, large lentigo melanoma in the face and melanoma in the eye, radiation therapy may be given. Radiation treatment of eye melanoma achieves similar results as enucleation but with some vision left. Enucleation is performed for large melanomas and / or involvement of the optic nerve.
As for skin melanomas, radiation sensitivity for melanomas in mucous membranes is variable, but they are not resistant. If the primary tumor is not too large and no distant metastases are present sugical treatment should be considered. For large melanomas where surgery will have to be extensive primary irradiation may be considered. Postoperative irradiation may also be an option. Fraction size is preferably > 2 Gy. Numerous regimens are mentioned in the literature. At Oslo University Hospital, commonly 2.5 Gy x 20 = 50 Gy is given postoperatively for mucosal melanomas.
Locoregional recurrence and distant metastases
Radiation treatment may provide palliation and local control of inoperable metastases which otherwise would have caused local problems.