In mantle cell lymphoma, whether 18 F-FDG PET/CT or flow cytometry provide superior diagnostic performance compared to biopsy in the determination of bone marrow involvement and enhance prognostic predictive value.

To investigate whether 18 F-FDG Positron Emission Tomography/Computed Tomography (PET/CT) and Flow Cytometry (FCM) can serve as alternatives to bone marrow biopsy (BMB) in diagnosing bone marrow involvement (BMI), prognostic prediction, and clinical application of mantle cell lymphoma (MCL). This retrospective analysis was conducted to assess the impact of PET/CT, FCM, and BMB results on BMI in 122 patients diagnosed with MCL who underwent PET/CT and bone marrow examinations, and 97 patients with complete survival data were included in the survival analysis. Taking BMB positive as the standard, the sensitivity of PET/CT was 57.4% (31/54), with a specificity of 55.9% (38/68). The positive predictive value (PPV) was 50.8% (31/61), while the negative predictive value (NPV) was 62.3% (38/61). A ratio of lymphoma cells exceeding 5.925% was defined as FCM positive (Supplemental Fig. 1), the sensitivity of FCM increased to 90.7% (49/54), and specificity was 77.9% (53/68). The PPV was 76.6% (49/64), and the NPV reached 91.4% (53/58). Multivariate analysis indicated that age, a MIPI score of 6 or higher, and morphological variants are independent prognostic factors for progression-free survival (PFS) and overall survival (OS) (all P < 0.05). The ratio of lymphoma cells ≥ 30% is an independent prognostic factor for PFS (P < 0.05). The PET/CT high-risk group showed lower PFS and OS than the control group, even though not an independent prognostic factor. The PFS prediction model incorporated the above independent prognostic factors and demonstrated excellent prognostic predictive value.