In this work, we report the preclinical evaluation of a novel PET imaging agent based on the 89Zr-labeled anti-mouse syndecan-1 mAb (9E7.4, IgG2a κ isotype) [19] in a subcutaneous model and a bone marrow disseminated MM model using desferrioxamine B (DFO) as chelator. Here, SDC1 is linked to Miyoshi myopathy.