The utility of 18-F-fluorodeoxyglucose positron emission tomography in evaluation of bone marrow involvement by non-Hodgkin lymphoma (NHL)

Abstract

8077 Introduction: In NHL, the anatomic extent of the disease is an important factor influencing the overall survival. Clinically, NHLs are classified as indolent, aggressive, or highly aggressive. Bone marrow (BM) involvement is a sign of extensive disease, and iliac crest (IC) BM biopsy (BMB) is the established method for the detection of BM infiltration. However, IC BMB is associated with a high rate of false- negative result. We assess the ability of 18F-FDG PET scan to ascertain the presence of BM involvement in NHL. Methods: We retrospectively reviewed charts from January 2002 through November 2006 of histologically proven NHLs. 87 patients (pts) were eligible for our study (38 males, 49 females; age range 42–81 years). All pts were examined by whole-body 18F-FDG-PET scan for initial staging, and all had unilateral posterior IC BMB. BM involvement was established following the result of 1) unilateral posterior IC BMB, and 2) image-guided BMB following positive 18F-FDG-PET scan in selected patients. Results: Among the PET+ / IC BMB- group, 3 pts had a positive CT-scan guided BMB at the site of involvement detected by the 18F-FDG-PET scan (2 from the humerus,1 from the femur); the remaining 7 pts did not have a site-directed biopsy. Our data demonstrate an overall sensitivity of 0.76 for the PET scan detecting BM involvement in all pts and specificity of 0.88. We point out that the 0.88 specificity may be spuriously low, this is a result of the fact that of the 10 PET+ / IC BMB- pts 7 have not had directed biopsy to the site of involvement detected by the18F-FDG- PET-scan. Further analysis revealed no significant difference between the sensitivity (P = 0.21) and specificity (p = 0.99) between I- NHL and A/HA- NHL groups. Conclusion: 18F-FDG-PET scan shows potential to detect BM involvement in NHL. In particular, image-guided repeat BMB may be considered in pts with negative initial IC BMB, whose 18F-FDG-PET scan demonstrates BM involvement in a different site. No significant financial relationships to disclose. [Table: see text]