OBJECTIVE
To investigate the prognostic value of 18F-FDG PET/CT scan quantization parameters, max standardized uptake value （SUVmax）, metabolic tumor volume （MTV）, total lesion glycolysis （TLG） and other clinical factors for prognostic evaluation of paticnts with diffuse large B-cell lymphoma （DLBCL）.
METHODS
PET/CT scan and clinical data of a total of 65 newly diagnosed DLBCL patients who received Rituximab plus cyclophosphamide, doxorubicin, vincristine and prednisone （R-CHOP） chemotherapy as first-line treatment were analyzed. All patients received a PET/CT scan at diagnosis and an interim PET/CT after 2-4 circles of chemotherapies. The related parameters of SUVmax, MTV and TLG were acquired by analyzing and calculating the scan results. The receiver operating characteristic （ROC） curve was used to determine the optimal cut-off of parameters. Pearson chi-square test, Kaplan-Meier method and COX proportional hazard model were performed to analyze the prognostic value of PET/CT related parameters and clinical factors in progression-free survival （PFS）.
RESULTS
Age, B symptom, Ann Arbor stage and extra-nodal involvement in major organs significantly related with PFS （P<0.05）, but the SUVmax didn't relalt with the prognosis. The cut-off values of MTV0, MTV1, TLG0 and TLG1 for disease recurrence or progression were 172.20cm 3, 4.32cm 3, 1043.33g and 14.07g. The lower MTV and TLG groups showed longer PFS significantly. In the multivariate Cox regression model, B symptoms, MTV1 and TLG1 were the independent prognostic risk factors.
CONCLUSION
MTV and TLG at baseline and in the interim and NCCN-IPI correlate with disease prognosis. SUVmax related parameters hare no significant relationship with prognosis. Besides MTV and TLG during treatment are the independent prognostic risk factors suggesting more predictive value than NCCN-IPI.