Positron emission tomography using 18-fluorodeoxyglucose in pre- and post-transplantation in lymphoma patients treated with autologous stem cell transplantation: Impact
8060 Background: The pre-transplant evaluation of lymphoma with Positron Emission Tomography (PET) scanning using 18- FluoroDeoxyGlucose may ease a decision making. The impact on patient outcome of post-transplant assessment is unknown. Methods: Between July 04 and December 05, patients (pts) who achieved tumor response and received high-dose chemotherapy plus autologous stem cell transplantation (ASCT) were explored with PET, prior and 100 days after ASCT, without knowledge of conventional imaging nor clinical history. PET results (negative or positive) were related to event-free survival (EFS) and overall survival (OS). Results: 60 pts were included. 50 had Non-Hodgkin Lymphoma (26 aggressive) and 10 Hodgkins Lymphoma. Median age was 52 [19-68]. 22 pts received front-line ASCT mainly after ACVBP (n=14) or CHOP. Platinum-based salvage chemotherapy was the most used (n=38), and most of the pts received rituximab (n=40). Prior ASCT,by clinical staging, there were 31 complete remission (CR), 23 uncertain CR and 6 partial remission. Conditioning regimen was BEAM in 39 pts; Zevalin BEAM in 11, Total Body Irradiation in 10. 75% were pre-ASCT-PET negative and 80% post-ASCT-PET negative. 6 pts (10%) converted from pre-ASCT-PET positive to post-ASCT-PET negative and 2 pts from negative to post-ASCT-PET positive. Median follow-up was 1.25 years [0.5–2]. 12 pts died (OS 80%) and 19 relapsed (EFS 68%). OS and EFS was better in pre-ASCT-PET-negative pts than in PET-positive (92% vs 53% (p=0.0009), 77% vs 35%, (p=0.0002) respectively). OS was estimated to 90% in post-ASCT-PET-negative pts vs 50% in PET-positive (p<0.0001), EFS was 79% vs 25%, respectively (p<0.0001). In multivariate analysis,including analysis by histology subtypes, the only adverse prognostic factor was PET positive either pre-ASCT (Relative Risk(RR)=4) or post-ASCT (RR=12). Conclusions: A positive PET after induction chemotherapy indicates a high risk of ASCT failure which is increased by a positive PET after ASCT. In pre-ASCT-PET-positive pts, more experimental approaches are required. In pre-ASCT-PET-negative patients, post-ASCT-PET assessment may be omitted. No significant financial relationships to disclose.