Objectives: This study was carried out to evaluate the role of quantitative parameters in staging PET in predicting prognosis in patients with high-grade non-Hodgkin's lymphoma (NHL).
Methods: A total of 51 histopathologically proven high-grade NHL patients treated with conventional chemotherapy regimens were included in the study. Total lesion glycolysis (TLG) and functional volumes (FVs) were defined as per the PET Response Criteria in Solid Tumors (PERCIST) criteria. All patients were followed up for a minimum period of 1 year or until an event, whichever occurred earlier.
Results: Of the four semiquantitative parameters studied, SUV max and SUV mean did not show a statistically significant correlation with progression-free survival or overall survival, whereas TLG and FV showed a weak but statistically significant negative correlation. Using the receiver operating characteristic curve analysis, optimal cut-offs were derived for FV and TLG to predict progression and death. Using the cut-off values of 416 cm3 and 3340 g for FV and TLG, respectively, a statistically significant difference in progression-free survival and overall survival was obtained in the groups with FV and TLG above and below the threshold. On multivariate analysis of all the conventional prognostic factors and TLG more than 3340 and FV more than 416 cm3, only age greater than 60 years (P=0.013) and FV more than 416 cm3 (P=0.012) were found to be independently associated with disease progression.
Conclusion: Our results indicate that FV and TLG in staging PET/CT could be useful indices in predicting outcomes in patients with high-grade NHL treated with standard first-line chemotherapy regimens.