Can fluorodeoxyglucose positron emission tomography/computed tomography avoid negative iliac crest biopsies in evaluation of marrow involvement by lymphoma at time of initial staging?

The assessment of bone marrow involvement (BMI) is important for accurate prognostication and deciding the appropriate therapy in patients with lymphoma. Conventional bilateral iliac crest biopsies (ILBMBs) have many limitations. F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) is a useful investigative tool for detecting BMI. F-18 FDG PET/CT data for 97 patients with either non-Hodgkin lymphoma (NHL) or Hodgkin lymphoma (HL) were analyzed. ILBMB was performed 7-10 days later. A final diagnosis of BMI was made in 38/97 patients on the basis of composite criteria derived from both FDG PET/CT and ILBMB results. ILBMB detected BMI in 29/38 patients, 2/5 patients with HL, 27/33 patients with NHL, 19/25 patients with aggressive NHL, and 8/8 patients with indolent NHL with a sensitivity of 76%, 40%, 82%, 76%, and 100%, respectively. FDG PET/CT was true positive for BMI in 5/5 patients with HL and 29/33 patients with NHL, comprising 25/25 patients with aggressive NHL and 4/8 patients with indolent NHL, with a sensitivity of 100%, 88%, 100%, and 50%, respectively. FDG PET/CT performed better than ILBMB in cases of HL and aggressive NHL, but its sensitivity was poor in cases of indolent lymphoma. In addition, FDG PET/CT had a very high negative predictive value approaching 100% in HL and aggressive NHL, which might help in avoiding negative ILBMBs.