A more precise method for determining bone marrow involvement in patients with diffuse large B-cell lymphoma has been identified by researchers in a study published recently in The Journal of Nuclear Medicine.1 Imaging with 18F–fluorodeoxyglucose positron-emission tomography/computed tomography (FDG PET/CT), when compared to bone marrow biopsy, was more sensitive, showed a higher negative predictive value, and was more accurate, changing treatment plan for 42% of patients with bone marrow involvement in the study.
“In our study, we showed that in diffuse large B-cell lymphoma, 18F-FDG PET/CT has better diagnostic performance than bone marrow biopsy to detect bone marrow involvement and provides a better prognostic stratification,” said Louis Berthet, MD, lead author of the study. “While bone marrow biopsy is considered the gold standard to evaluate bone marrow involvement by high-grade lymphomas, 18F-FDG PET/CT is in fact the best method to evaluate extension of the disease, as well as avoid invasive procedures.”
The retrospective study included 133 patients diagnosed with diffuse large-cell B-cell lymphoma. All patients received both a whole-body 18F-FDG PET/CT scan, as well as a bone marrow biopsy to determine bone marrow involvement.
A final diagnosis of bone marrow involvement was made if the biopsy was positive, or if the positive PET/CT scan was confirmed by a guided biopsy, by targeted magnetic resonance imaging or, after chemotherapy, by the concomitant disappearance of focal bone marrow uptake and uptake in other lymphoma lesions on 18F-FDG PET/CT reassessment. Progression-free survival and overall survival were then analyzed.
A total of 33 patients were considered to have bone marrow involvement. Of these, 8 were positive according to the biopsy and 32 were positive according to the PET/CT scan. 18FDG PET/CT was more sensitive (94% vs 24%), showed a higher negative predictive value (98% vs 80%), and was more accurate (98% vs 81%) than bone marrow biopsy. Among the 26 patients with positive 18F-FDG PET/CT results and negative biopsy results, 11 were upstaged to stage IV by PET/CT, which changed their treatment plans. 18F-FDG PET/CT was also determined to be an independent predictor of progression-free survival.
“Our findings add to the literature to prove the significance of 18F-FDG PET/CT in cancer evaluation and to democratize this imaging method,” said Dr. Berthet. ■
Disclosure: The study authors reported no potential conflicts of interest.
1. Berthet L, Couchet A, Kanoun S, et al: J Nucl Med 54:1244-1250, 2013.