Comparison of automated robotic arm-assisted PET/computed tomography–guided metabolic bone marrow biopsy with conventional bone marrow trephine biopsy for evaluating bone marrow infiltration in newly diagnosed lymphoma

OBJECTIVES: Bone marrow involvement (BMI) upstages lymphoma and influences prognosis and treatment. Conventional bone marrow trephine biopsy (BMTB) may miss patchy or extrapelvic disease. This study compared the diagnostic performance of automated-robotic-arm (ARA)-assisted 18 F-fluorodeoxyglucose (FDG) PET/computed tomography (CT)-guided bone marrow biopsy with BMTB in treatment-naive lymphoma. METHODS: In this prospective single-centre study, 169 treatment-naive lymphoma patients underwent baseline 18 F-FDG PET/CT and bilateral posterior iliac crest BMTB. Among these, 44 patients with focal FDG-avid marrow lesions (unifocal or multifocal) underwent ARA-assisted PET/CT-guided bone marrow biopsy. Histopathological findings from PET/CT-guided biopsy and BMTB were used to establish the final diagnosis of BMI. Diagnostic performance parameters were calculated with 95% confidence intervals (CIs) using Wilson score method. Comparisons were performed using Fisher's exact test. RESULTS: Of the 44 patients with focal FDG-avid marrow lesions, 40 had lymphomatous BMI on final diagnosis. PET/CT-guided biopsy yielded 37 true positives, four true negatives, and three false-negatives, with no false-positive. Sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy were 92.5% (95% CI: 80.1-97.4%), 100% (95% CI: 51.0-100.0%), 100% (95% CI: 90.6-100.0%), 57.1% (95% CI: 25.0-84.2%), and 93.2% (95% CI: 81.8-97.7%), respectively. Conventional BMTB demonstrated significantly lower sensitivity (52.5%) and accuracy (56.8%) ( P < 0.001). CONCLUSION: ARA-assisted PET/CT-guided metabolic bone marrow biopsy demonstrates superior sensitivity and accuracy than conventional iliac crest trephine biopsy. It improves detection of lymphomatous BMI, boosts diagnostic confidence and reduces over-staging risk. It may play a selective problem-solving tool for focal FDG-avid marrow lesions.