3. 3. Age >/= 18. All minor patients will be excluded to avoid excessive radiation dose. There is data suggesting small but statistically significant increased risk for secondary malignancy due to the cumulative dose of radiation exposure associated with diagnostic imaging. Children are most sensitive to radiation long term adverse effects. Therefore current pilot study will accrue adults only. If the result of this study will indicate potential advantage of PET-CT, this data can be weighted against radiation exposure risks to decide upon imaging strategies in pediatric patients with melanoma.