This is a single BNCT-facility, non-randomized, non-comparative, open-label, phase I to II clinical trial to determine the value of IHNI in the performance of BNCT. Before patients are recruited in this study, they must have been confirmed as malignant melanoma by biopsy and pathological analysis. Then they will receive a boron bio-distribution test, only patients whose boron concentration in tumor tissue is >1.5 times that in the blood will be enrolled. Before patients being irradiated in IHNI, they will be infused Boronophenylalanine (BPA)-fructose solution intravenously at a dose of 350mg/kg over 90 minutes, and then blood will be withdrawn from the patient at different time points to measure boron concentration. The start point and duration of irradiation will be determined based on the boron concentration in blood and the boron bio-distribution curve.