Inclusion Criteria:  18-75 years old; ECOG score 0 or 1 point; Participants with suspected or confirmed non-small cell lung cancer or melanoma who are suggested by the clinicians to conduct PET/CT imaging for tumor diagnosis or staging.  Exclusion Criteria:  Pregnant or nursing; Severe hepatic or renal dysfunction; Low WBC (less than 3 x 10^9/L); Unable to comply with the PET/CT imaging procedures.