Positron emission tomography (PET) with 18F-fluorodeoxyglucose (18F-FDG) for the staging of low-grade non-Hodgkin's lymphoma (NHL).

Background:Although PET has been shown to be highlysensitive in the primary staging of lymphoma, previous studies withsmall numbers of patients indicated that low-grade NHL may not always beadequately detected by PET. We undertook this study to determine factorsinfluencing the detection of lesions by PET in low-grade NHL and toevaluate the utility of PET in this indication.Patients and methods:Forty-two patients underwentconventional staging procedures (clinical examination,oto-rhino-laryngologic examination, computed tomography of the chest,abdomen and pelvis, gastroscopy and bone marrow biopsy as well aswhole-body non-attenuation corrected ¹⁸F-FDG-PET.Results:PET detected 40% more abnormal lymph nodeareas than conventional staging in follicular lymphoma but wasinappropriate for the staging of small lymphocytic lymphoma where itdetected less than 58% of abnormal lymph node areas. PET showedmore lesions than conventional staging for peripheral (34% morelymph node areas detected) and thoracic lymph node (39% more)areas but not for abdominal or pelvic lymph nodes (26% fewerareas detected). The sensitivity to detect bone marrow infiltration wasunacceptably low for PET. In contrast, PET was as effective as standardprocedures for the detection of other extranodal localizations, althougha few localizations were detected only by PET and a few others only byconventional procedures.Conclusions:PET may contribute to the management ofpatients with low-grade follicular NHL. For the other low-grade lymphomasubtypes, the role of PET is less evident. Further studies using PET toevaluate the results of treatment or to diagnose disease recurrence arewarranted in low-grade follicular NHL.