To be eligible for this study, patients must have a confirmed diagnosis of AL amyloidosis without significant cardiac (New York Heart Association class IV) disease and not be on kidney dialysis. Additionally, after testing, their blood must not contain antibodies to mouse proteins. The study requires an intravenous infusion, given over 10 minutes, of the radiolabeled antibody, followed 48 hours later by a PET/CT scan. A repeat scan is done 5 to 7 days after infusion of the antibody. A 5 ml blood specimen needs to be furnished 4 and 8 weeks after the antibody infusion.
