Prognostic values of interim and post-therapy 18F-FDG PET/CT scanning in adult patients with Burkitt's lymphoma.

Background: The prognostic values of interim and post-therapy fluorine-18-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET) and PET/computed tomography (CT) scanning have been confirmed in several subtypes of lymphoma. However, its prognostic value in Burkitt's lymphoma has not been clearly defined. The aim of the present study was to assess the prognostic value of PET/CT scanning during different treatment processes of Burkitt's lymphoma.

Methods: A total of 29 adult patients with newly diagnosed Burkitt's lymphoma were retrospectively involved in this study; of them, 23 patients underwent baseline PET/CT, 15 patients underwent mid-therapy PET/CT after 1-4 cycles of chemotherapy, and 17 patients underwent post-therapy PET/CT after all planned first-line chemotherapy cycles. Mid-therapy and post-therapy PET/CT results (positive vs. negative) were visually interpreted according to the criteria of the International Harmonization Project. The reduction in the maximum standardizes uptake values (∆SUVmax) of 25%, 50%, and 75% were regarded as cutoff points. Overall survival (OS) and progression-free survival (PFS) were regarded as the major endpoints.

Results: The median OS and PFS were 27.6 months (range 6.5-78.3 months) and 27.2 months (range 3.0-78.3 months), respectively. The median SUVmax of the baseline PET/CT was 18.3 (range 1.6-35.9), whereas the median SUVmax of the mid-therapy and post-therapy PET/CT decreased to 4.0 (range 0-17.6) and 3.0 (range 0-14.5), respectively. The patients' Eastern Cooperative Oncology Group (ECOG) scores (<2 vs. ≥2) were significantly associated with the baseline PET/CT SUVmax. The mid-therapy and post-therapy PET/CT results (positive vs. negative) showed no significant association with OS or PFS. The optimal cutoff ∆SUVmax from the baseline to the post-therapy PET/CT that could predict a change in OS in patients with Burkitt's lymphoma was 50% (P = 0.019).

Conclusions: (18)F-FDG uptake was intense in Burkitt's lymphoma, and there was a significant reduction in SUVmax during the interim and post-therapy PET/CT procedures. A ∆SUVmax of greater than 50% was a favorable cutoff point to predict the OS of Burkitt's lymphoma patients.