The relationship between immunohistochemical parameters and bone marrow fibrosis and bone marrow 18 F-FDG uptake in multiple myeloma patients undergoing PET/CT examination.

PURPOSE: The aim of this study was to determine the power of the SUVmax value obtained from 18 F-FDG PET/CT in multiple myeloma (MM) patients to be able to predict immunophenotype characteristics (CD20, CD44, CD56, CD117, CD138 antigen expressions), bone marrow fibrosis, cyclin D1 oncogene, and M-protein subtypes which play a role in diagnosis-treatment and prognosis of the disease.

MATERIAL AND METHOD: The study included 54 patients with multiple myeloma who underwent PET/CT for initial staging and bone marrow biopsy. The relationship was examined in these patients between the SUVmax value measured from the iliac bone region and the immunohistochemical and bone marrow fibrosis data of the biopsy taken from the iliac bone. The Mann Whitney U-test was used in the comparisons of dependent paired groups, and the Kruskal Wallis H test in the comparisons of three or more groups.

RESULTS: The median SUVmax value was 4.5 (1.9-15.6) in patients with CD117 antigen positivity, which was statistically significantly higher than the value in the patients with CD117 negativity (p = 0.031). When patient grouping was made according to the reticulin level; We found that the median SUVmax value was 4.9 (3.0-14.8) in the group with increased fibrosis and 3.6 (1.6-15.6) in the group with low fibrosis. The median SUVmax was statistically significantly higher in the group with increased fibrosis compared to the group with low fibrosis (p = 0.004). No statistically significant difference was determined in the comparisons of the SUVmax values when the patients were grouped according to the immunoglobulin heavy chain and light chain, CD20, CD44, CD56, and cyclin D1 characteristics (p > 0.05).

CONCLUSION: In MM patients who underwent PET/CT for initial staging, significant relationships were determined between FDG uptake in the bone marrow (SUVmax) and CD117 antigen and bone marrow fibrosis, which is an important prognostic factor. Higher SUVmax values were determined in the bone marrow of patients with increased fibrosis and CD117 positivity.