Value of 18F-FDG coincidence SPECT imaging for predicting the clinical outcome of patients with non-Hodgkin's lymphoma prior to and after autoiogous stem cell transplantation

Objective Evaluation of therapeutic response in non-Hodgkin's lymphoma (NHL) pa-tients with autologous stem cell transplantation (ASCT) is of great clinical significance. But the exact role of 18F-fluorodeoxyglucose (FDG) imaging in NHL associated with ASCT is not clear. This study assessed the value of 18F-FDG coincidence SPECT imaging prior to and after ASCT for prediction of progression-free sur-vival (PFS) in NHL, as well as the predictive values of CT and 18F-FDG SPECT imaging in these patients. Methods 18F-FDG coincidence SPECT imaging and CT were performed in 29 patients with pathologically confirmed NHI. prior to and after ASCT. No patients were lost to follow-up earlier than 1 year after ASCT. Positive predictive value ( PPV), negative predictive value (NPV) and accuracy of 18 F-FDG coincidence SPECT imaging were compared to the results of CT using the X2-test. The results of 18F-FDG scans and CT were correlated with PFS using Kaplan-Meier survival analysis. Results 18F-FDG coincidence SPECT ima-ging before ASCT showed PPV, NPV and accuracy [85.7% ( 12/14), 73.3% ( 11/15 ) and 79.3% ( 23/29)] higher than CT [55.6% (10/18), 45.5% (5/11) and 51.7% (15/29), respectively]. After ASCT, 18F-FDG imaging also showed PPV, NPV and accuracy [92.3% (12/13), 75.0% (12/16) and 82.8% (24/29)] higher than CT[62.5%(10/16), 53.8% (7/13) and 58.6% (17/29), respectively]. However, only the differences in accuracy between 18 F-FDG SPECT imaging and CT before and after ASCT were significant ( X2 =4.884, 4.077, all P<0.05). 18F-FDG imaging results before or after ASCT were strongly correlated with PFS (X2 =15.839, 20.219, all P<0.005, significant) but not CT(X2=2.468, P= 0.116, not significant). The 1-year PFS rate for 18F-FDG-negative patients was 86.7% ( 13/15 ) and 28.6% (4/14) for 18SF-FDG-positive patients before ASCT. The 1-year PFS rate for18F-FDG-negative patients was 87.5% (14/16) and 23.1% (3/13) for 18F-FDG-positive patients after ASCT. Conclusion 18F-FDG coincidence SPECT imaging before or after ASCT can be used to predict the post-ASCT outcome of NHL patients better than CT. Key words: Lymphoma, non-Hodgkin's;  Stem cells;  Transplantation, autologous;  Coincidence;  Tomography, emission-computed, single-photon;  Deoxyglucose