The utility of ¹⁸F-FDG PET/CT in assessing bone marrow involvement and prognosis in newly diagnosed diffuse large...

The presence of bone marrow involvement (BMI) in patients with diffuse large B-cell lymphoma (DLBCL) has a significant impact on treatment plans and prognosis, but clinical diagnosis is difficult. The purpose of this study was to evaluate the utility of PET/CT in the assessment of BMI and prognosis in newly diagnosed DLBCL.

This retrospective study included 57 eligible DLBCL patients who underwent bone marrow biopsy (BMB) and PET/CT prior to any treatment initiation. Increased FDG uptake in the bone marrow on PET/CT scans was indicative of BMI positivity, with such instances not attributable to benign findings. If BMB yielded positive results, or if the marrow uptake resolved concurrently with other lymphoma lesions during PET/CT monitoring, the diagnosis of BMI was established. The evaluation of bone marrow status via PET/CT involved both visual analysis and a quantitative index, specifically the ratio of maximum standardized uptake values of bone marrow to liver (BLR). Factors associated with 2-year progression-free survival (PFS) was analyzed utilizing the Cox proportional hazards regression model.

34 patients were diagnosed with BMI. PET/CT demonstrated superior accuracy (93.0% vs. 75.4%) and sensitivity (94.1% vs. 58.8%) compared to BMB. During the follow-up period, 15 patients experienced disease progression. Survival analysis identified Eastern Cooperative Oncology Group performance status (ECOG PS), BLR, and PET/CT bone marrow status as the sole independent predictors of PFS (p = 0.010, 0.002, and 0.015, respectively).

PET/CT played an important role in evaluating BMI and predicting PFS in newly diagnosed DLBCL.