High diffuse bone marrow uptake in 18F-FDG PET/CT may reflect the diverse mutational characteristics of multiple myeloma.

The most frequently identified mutant gene in newly diagnosed multiple myeloma patients was ATM, followed by HUWE1, PABPC1, and TP53.

• Targeted sequencing was performed on bone marrow samples using a customized panel covering 80 genes relevant to MM biology.
• Fourteen newly diagnosed patients with MM who underwent 18F-FDG PET/CT at diagnosis were retrospectively reviewed.
• The study used targeted DNA sequencing to characterize the mutational landscape.

Patients with high diffuse FDG uptake (high DU) in bone marrow showed a higher tumor burden than those with low diffuse uptake (low DU).

• Fourteen newly diagnosed MM patients were classified into high DU and low DU groups based on their PET/CT findings.
• Higher tumor burden was observed in the high DU group compared to the low DU group.
• The study was retrospective in design with a small cohort of 14 patients.

Patients with high diffuse bone marrow FDG uptake were likely to have inferior overall survival compared to those with low diffuse uptake.

• Overall survival outcomes were compared between high DU and low DU patient groups.
• The finding was based on a retrospective review of 14 newly diagnosed MM patients.
• Inferior survival in high DU patients was associated with diverse mutational characteristics.

Mutations detected in patients with high diffuse uptake were associated with various oncogenic pathways relevant to MM disease progression, with epigenetic regulator pathways predominantly enriched.

• Pathways involving epigenetic regulators were predominantly enriched in patients with high DU.
• Mutations in high DU patients were linked to various oncogenic pathways relevant to the disease progression of MM.
• The diverse mutational characteristics were described as potentially reflecting the heterogeneous nature of MM.

In serial PET/CT and sequencing follow-ups after first-line treatment, a patient with residual PET/CT findings showed emergence of new mutations, while patients with complete resolution of PET/CT abnormalities demonstrated improved mutational characteristics.

• Seven patients underwent serial PET/CT and sequencing after first-line treatment.
• Emergence of new mutations was observed in the patient with residual PET/CT findings.
• Patients with complete resolution of PET/CT abnormalities demonstrated improved mutational characteristics.
• This serial analysis suggests a dynamic relationship between PET/CT findings and mutational evolution during treatment.