For Multiple Myeloma, Add-on Minimally Invasive Scan Predicts Prognosis

Flow cytometry plus positron emission tomography/computed tomography (PET/CT) scanning is beneficial for detecting minimal residual disease after stem cell transplantation for patients with multiple myeloma (MM), according to new study results presented at the American Society of Hematology’s 2021 Annual Meeting.

To examine the prognostic value of flow cytometry plus PET/CT scanning for detecting minimal residual disease (MRD) in patients with MM, researchers at China’s Sun Yat-Sen University conducted an observational cohort study of 94 consecutive patients.

To be eligible for the study, patients had to be newly diagnosed with MM, be transplant-eligible, and have received a PET/CT scan before initiating antimyeloma induction therapy—consisting of bortezomib, doxorubicin, and dexamethasone—preceding autologous stem cell transplantation.

Whole-body 2-deoxy-2-[fluorine-18]fluoro-D-glucose (18F-FDG) PET/CT scans were conducted at baseline and repeated after induction therapy and 6, 12, and 24 months after transplantation. A 5-point Deauville scale score (DSS) was used to evaluate 18F-FDG uptake in bone marrow and focal lesions. In addition, MRD status was analyzed by using 8‑color multiparameter flow cytometry. A Cox proportional hazards model was used to analyze the prognostic value of the results of this imaging.

Using these methods, the researchers found that the results of flow cytometry and the DSS applied to the PET scans differed dramatically both after induction and at 6 and 12 months after transplantation. However, when a cutoff of DSS 3 was used at month 24 after transplantation, agreement between the 2 assessments improved considerably.

The researchers also found that patients with a DSS of 1 to 2 at each time point after transplantation had a similar favorable time to progression, but patients with a DSS of 3 to 4 at each time point had a similar poor time to progression.

According to the researchers, “Patients with a low Deauville score (1–2) had a good prognosis at different time points no matter the MRD status, reflecting the importance of PET/CT.”

—Ellen Kurek

Reference:

Gu J, Li J. Prognostic value of flowcytometric minimal residual disease combined with PET/CT at multiple time points before and after autologous stem cell transplantation in multiple myeloma. Paper presented at: American Society of Hematology’s 2021 Annual Meeting; December 8-14, 2021; Atlanta, Georgia, and Virtual. https://ash.confex.com/ash/2021/webprogram/Paper145018.html