The role of bone marrow biopsy and FDG-PET/CT in identifying bone marrow infiltration in the initial diagnosis of high grade non-Hodgkin B-cell lymphoma and Hodgkin lymphoma. Accuracy in a multicenter series of 372 patients.

Bone marrow infiltration (BMI), categorized as an extra-nodal site, affects stage and is associated with poor prognosis in newly diagnosed lymphoma patients. We have evaluated the accuracy of PET/CT and bone marrow biopsy (BMB) to assess BMI in 372 lymphoma patients [140 Hodgkin Lymphoma (HL) and 232 High Grade B-cell non-Hodgkin Lymphoma (HG B-NHL), among them 155 Diffuse Large B-Cell Lymphoma (DLCL)]. For HL cases, and taking into account PET/CT, sensitivity, negative predictive value (NPV) and accuracy were 96.7, 99.3, and 99.3% while those of BMB were 32.3, 83.8, and 85%, respectively. For HG B-NHL and considering PET/CT, sensitivity, NPV, and accuracy were 52.7, 81.7, and 84.1%, while those of BMB were 77.6, 90.2, and 90.7%, respectively. In the HG B-NHL group, 25 patients would have been under-staged without BMB. These results lead us to recommend PET/CT and the avoidance of BMB to assess BMI in HL. In the case of HG B-NHL, bone marrow status should be assessed firstly by means of PET/CT; only in either focal or diffuse PET/CT with low borderline SUV max values or in negative cases, should BMB be carried out afterwards. In the HG B-NHL setting and at the present moment, both techniques are complementary.

Bone marrow biopsy superiority over PET/CT in predicting progression-free survival in a homogeneously-treated cohort of diffuse large B-cell lymphoma.

Several studies have reported uneven results when evaluating the prognostic value of bone marrow biopsy (BMB) and PET/CT as part of the staging of diffuse large B-cell lymphoma (DLBCL). The heterogeneity of the inclusion criteria and not taking into account selection and collinearity biases in the analysis models might explain part of these discrepancies. To address this issue we have carried a retrospective multicenter study including 268 DLBCL patients with a BMB and a PET/CT available at diagnosis where we estimated both the prognosis impact and the diagnostic accuracy of each technique. Only patients treated with R-CHOP/21 as first line (n = 203) were included in the survival analysis. With a median follow-up of 25 months the estimated 3-year progression-free survival (PFS) and overall survival (OS) were 76.3% and 82.7% respectively. In a multivariate analysis designed to avoid a collinearity bias with IPI categories, BMB-BMI [bone marrow involvement](+) (HR: 3.6) and ECOG PS > 1 (HR: 2.9) were independently associated with a shorter PFS and three factors, age >60 years old (HR: 2.4), ECOG PS >1 (HR: 2.4), and abnormally elevated B2-microglobulin levels (HR: 2.2) were independently associated with a shorter OS. In our DLBCL cohort, treated with a uniform first-line chemotherapy regimen, BMI by BMB complemented performance status in predicting those patients with a higher risk for relapse or progression. In this cohort BMI by PET/CT could not independently predict a shorter PFS and/or OS.