A dose escalation schema will be used with the initial patient receiving the current lowest dose of nonradiolabeled AHN-12 (from 0.20 mg/kg to 1.0 mg/kg). If a favorable biodistribution is not achieved and the patient remains negative for HAMA, the infusion may be repeated up to two more times (with a one level increase in nonradiolabeled AHN-12 each time) in an attempt of achieving favorable biodistribution.