PROTON RADIOTHERAPY FOR MALIGNANT-MELANOMA OF THE SKIN

Background: Malignant melanoma, a tumor with reduced radiosensitivity, has been suggested to be overcome by a high-dose fractionation radiotherapy. The proton beam presents physical characteristics that enable such high-dose irradiation. Objective: Our aim is to answer whether or not the proton beam can provide useful treatment for cutaneous melanoma. Methods: Five primary melanomas (4 acral lentiginous and 1 superficial spreading type) and 3 metastatic lymph nodes of 3 different patients were irradiated using the proton beam with a total dose of around 100 Gy fractionated into single doses of approximately 10 Gy. Results: All the macular lesions and a tumor lesion of primary melanoma disappeared completely, and other tumor lesions regressed by 80-90%. The 3 metastatic lymph nodes also regressed by 50-90%, No severe radiation-related complication occurred. Conclusion: Proton radiotherapy may prove to be a useful therapeutic modality for the management of cutaneous malignant melanoma.