68Ga-pentixather and 68Ga-pentixafor PET/CT in Multiple Myeloma

Comparison of 68Ga-pentixather and 68Ga-pentixafor PET/CT in Patients With Multiple Myeloma

Chemokine receptor-4 (CXCR4) is overexpressed in multiple myeloma (MM) cells. 68Ga-pentixafor is a radio-labled tracer for CXCR4 . 68Ga-pentixafor PET/CT has shown good diagnostic performance in MM. But an exchange of Ga3+ by Lu3+ or Y3+ will lead to a significant loss of CXCR4 affinity. Investigators conduct this prospective study to evaluate the diagnostic performance of 68Ga-pentixather compared with 68Ga-pentixafor, in order to parallel 68Ga-pentixather and 177Lu/90Y-pentixather in theranostics of MM.

Multiple myeloma (MM) is a malignant plasma cell disorder which is characterized by clonal proliferation of plasma cell in bone marrow microenvironment. Chemokine receptor-4 (CXCR4) is overexpressed in MM cells, and has been identified as a potential therapy target. 68Ga-pentixafor is a radiolabeled ligand with high affinity for CXCR4. 68Ga-pentixafor PET/CT has been reported with better diagnostic performance than 18F-FDG PET/CT. However, considering both diagnostic and therapeutic applications, an exchange of Ga3+ by other M3+ ions (Lu or Y) will lead to a significant loss of CXCR4 affinity. Thus, pentixather was developed as the precursor of 177Lu-pentixather or 90Y-pentixather, which can be used in CXCR4-targeted peptide receptor radionuclide therapy (PRRT). Investigators conduct this prospective study to evaluate the diagnostic performance of 68Ga-pentixather compared with 68Ga-pentixafor, in order to parallel 68Ga-pentixather and 177Lu/90Y-pentixather in theranostics of MM.

Inclusion Criteria:

1. Suspected or confirmed untreated multiple myeloma (MM), relapsed MM, MM in remission
2. Signed written consent

Exclusion Criteria:

1. pregnancy
2. breastfeeding
3. known allergy against pentixather or pentixafor
4. any medical condition that in the opinion of the investigator, may significantly interfere with study compliance.