Imaging Study of [89Zr]DFO-YS5 for Detecting CD46 Positive Malignancy in Multiple Myeloma

Inclusion Criteria: * Participants must have histologically or cytologically confirmed multiple myeloma by International Myeloma Working Group (IMWG) diagnostic criteria * At least one positive myelomatous lesion found on 18F-FDG PET/CT or PET/MRI. A positive lesion is defined as uptake greater than liver on FDG PET, based on the Italian myeloma criteria for PET use (IMPeTUs) criteria * Age \>= 18 years * Total bilirubin =\< 1.5 X institutional upper limit of normal (ULN) * Aspartate aminotransferase (AST) =\< 3 X ULN * Alanine aminotransferase (ALT) =\< 3 X ULN * Creatinine clearance \>= 30 mL/min, calculated using the Cockcroft-Gault equation or serum creatinine \<= 1.5x the institutional upper limit of normal. * Ability to understand a written informed consent document, and the willingness to sign it Exclusion Criteria: * Any condition that, in the opinion of the principal investigator, would impair the participants' ability to comply with study procedures or interfere with the safety of the investigational regimen * Individuals who are pregnant or breastfeeding/chestfeeding. * \- Breast-feeding/chest-feeding should be discontinued before administration of \[89ZR\]DFO-YS5. * Females of childbearing potential must have a negative urine or serum pregnancy test (i.e., human chorionic gonadotropin test) within 72 hours prior to administration of \[89ZR\]-DFO-YS5. * \- If the urine pregnancy test is positive or equivocal, a confirmatory serum pregnancy test is required. In such cases, the individual must be excluded from participation if the serum pregnancy result is positive. * \- A female is considered to be of childbearing potential (regardless of sexual orientation, having undergone a tubal ligation, or remaining celibate by choice), unless it is documented that the individual meets either of the following two criteria: (1) has reached a postmenopausal state ( \>= 12 continuous months of amenorrhea with no identified cause other than menopause); or (2) has undergone surgical sterilization (i.e., hysterectomy and/or bilateral oophorectomy for removal of uterus and/or ovaries). * Individuals who are pregnant or breastfeeding/chestfeeding are excluded because there is an unknown but potential risk for adverse effects in the unborn/nursing child secondary to treatment of the study participant with \[89ZR\]-DFO-YS5