18-F-fluorodeoxyglucose-positron emission tomography as a new approach to detect lymphomatous bone marrow.

PURPOSE

Bone marrow involvement in patients with malignant lymphoma is considered a sign of generalized disease with less favorable prognosis. Bone marrow biopsy (BMB), which represents the standard diagnostic procedure, however, is associated with a high rate of false-negative findings, which may lead to errors in management. The present study was undertaken to investigate the efficacy of positron emission tomography (PET) with 18-F-fluorodeoxyglucose (FDG-PET) as a new method to evaluate bone marrow involvement in patients with malignant lymphoma.

METHODS

Seventy-eight consecutive, untreated patients with either non-Hodgkin's lymphoma (NHL; n = 39) or Hodgkin's disease (HD; n = 39) were prospectively evaluated. Static FDG-PET imaging was performed following application of 270 MBq (F-18)-FDG. Attenuation correction was performed in 63 of 78 patients. Visual evaluation was performed by two examiners unaware of the clinical data. Material for BMB (70 bilateral, 8 unilateral) was obtained from the posterior iliac crest. Discordant results of PET and biopsy were settled, when possible, on the basis of further biopsy or magnetic resonance imaging (MRI).

RESULTS

In addition to seven concordant positive and 57 concordant negative findings, biopsy revealed another four cases with bone marrow involvement not detectable by FDG-PET analysis (+5.1%). On the contrary, PET showed bone marrow areas of intensive FDG uptake that suggested bone marrow lymphoma in 10 patients with negative biopsies (+12.8%). In eight patients, FDG-PET findings were confirmed by either histologic verification (n = 4), MRI (n = 2), polymerase chain reaction (PCR) for rearranged immunoglobulin H sequences (n = 1), or clinical presentation (n = 1). Two cases remained unresolved.

CONCLUSION

The results indicate that FDG-PET has a high potential to detect bone marrow involvement in malignant lymphoma. Besides confirming lesions found at BMB, FDG-PET provided additional information, which, in eight of 78 patients (10.3%), led to an upgrade of the tumor stage.