The aim of this study is the safety and efficacy of high-activity natural killer immunotherapy to small metastases of melanoma.

By enrolling patients with small metastases of melanoma adapted to enrolled criteria, this study will document for the first time the safety and the short and long term efficacy of high-activity natural killer cells.

The safety will be evaluated by statistics of adverse reactions. The efficacy will be evaluated according to local relief degree, progress free survival (PFS) and overall survival (OS).

Inclusion Criteria:

• All standard therapies have failed according to NCCN guidelines or the patient refuses standard therapies after cancer recurrence
• Body tumor 1-6, the maximum tumor length < 2 cm
• KPS ≥ 70, lifespan > 6 months
• Platelet count ≥ 80×109/L，white blood cell count ≥ 3×109/L, neutrophil count ≥ 2×109/L, hemoglobin ≥ 80 g/L

Exclusion Criteria:

• Patients with cardiac pacemaker
• Patients with brain metastasis
• Patients with grade 3 hypertension or diabetic complication, severe cardiac and pulmonary dysfunction