Diagnostic accuracy of 18F-FDG PET/CT in bone marrow disease detection in newly diagnosed lymphoma patients: a single institution experience
Introduction: Evaluation of bone marrow involvement in newly diagnosed lymphoma patients is very crucial. Presence of bone/bone marrow infiltration dictates much the course of treatment and prognostication of the disease.
Objective: The aim of the study is to evaluate the diagnostic accuracy of 18F-FDG PET/CT in the detection of bone marrow disease in newly diagnosed lymphoma patients.
Methods: A retrospective study was done of 35 newly diagnosed, biopsy-proven cases of lymphoma performed in January 2010 to October 2015 from the institution’s database. Included in the study were those who underwent 18F-FDG-PET/CT scan with bone marrow biopsy (BMB) in the same institution. Bone/ bone marrow uptake seen in the 18F-FDG PET/CT scan were reviewed. Bone marrow results of all patients were also reviewed and were correlated with 18F-FDG-PET/CT findings using Spearman’s statistical correlation. Using the BMB as reference, sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of 18F-FDG in detecting marrow involvement were calculated. Results: There were 35 patients in total, 18 (51%) male and 17 (49%) female. The age range was from 13 to 81 years (mean age: 47 years). 18F-FDG PET/CT was reported as negative for bone/bone marrow involvement in 22 (63%) patients while the remaining 13 (37%) showed abnormal FDG uptake; 8 (62%) of which showed diffuse FDG uptake and 5 (38%) showed multifocal FDG uptake. Seven out of 13 who showed positive FDG uptake in bone/bone marrow had BMB evidence of disease involvement and 6 had negative BMB result. The overall sensitivity of 18F-FDG-PET/CT was calculated to be 100%, the specificity was 79%, the negative predictive value was 100%, positive predictive value was 54%, and the diagnostic accuracy was 83%. Spearman’s correlation demonstrated good correlation between 18F-FDG PET/CT scan findings and bone marrow biopsy findings (Spearman’s rho = 0.65; p-value > 0.0001).
Conclusion: High sensitivity, specificity, and diagnostic accuracy of 18F-FDG PET/CT, as well as a good correlation with bone marrow biopsy result, manifested in this study may confirm the claim that 18F-FDG PET/CT complements bone marrow biopsy if not an alternative to BMB in detecting bone marrow involvement in newly diagnosed, untreated lymphoma patients. 18-F FDG PET/CT may also help increase the positive yield of bone marrow biopsies by guiding the marrow sampling procedures to sites of relatively hypercellular marrow.