FDG-PET/CT Provides Clues on Bone Marrow Involvement in Follicular Lymphoma and Carries Important Prognostic Information.

To compare the diagnostic efficacy of PET-CT and bone marrow biopsy (BMB) in the detection of bone marrow involvement (BMI) in newly diagnosed patients with follicular lymphoma (FL), as well as their prognostic implications in such patients. Retrospective analysis was conducted on clinical data from 165 newly diagnosed FL patients. The benefits and drawbacks of PET-CT and BMB in assessing BMI in FL patients were compared and evaluated. Moreover, the prognostic outcomes and factors affecting the survival of FL patients were examined. Among 165 patients, bone marrow involvement (BMI) was diagnosed by PET-CT (PET) in 54 cases (32.7%), by bone marrow biopsy (BMB) in 50 cases (30.3%), and by either PET or BMB in 80 cases (48.5%). PET-CT scans upgraded 32 patients (19.4%) to stage IV, including 1 stage I and 4 stage II cases. Four patients were elevated to stage IV by BMB, all of whom had a previous stage III diagnosis. No patients with previous stages I or II were elevated to stage IV by BMB. The median follow-up time was 6.6 years (range,0-11.0 years). The 5-year OS was 86.7%, and the 5-year PFS was 44.8%. Multivariate analysis revealed that BMI by PET-CT was the only independent predictor of PFS reduction. Regarding OS, grade 3a and BMI by PET-CT were independent predictors of decreased survival. PET-CT enables a thorough evaluation of bone marrow involvement in patients with FL, and BMI identified by PET-CT can have substantially implications for patient prognosis. PET-CT obtains vital data for the diagnosis, treatment, and prognosis of FL patients. By contrast, BMB seldom augments crucial data.