Prognostic value of baseline, interim and end-of-treatment 18F-FDG PET/CT parameters in extranodal natural killer/T-cell lymphoma: A meta-analysis

The prognostic value of F-18-fluorodeoxyglucose positron emission tomography-computed tomography (F-18-FDG PET/CT) in extranodal natural killer/T-cell lymphoma (ENKTL) is currently controversial. Furthermore, whether the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), total lesion glycolysis (TLG) and Deauville 5-point scale (DS) acquired from PET/CT are predictors of prognosis in ENKTL remains unclear. The aim of this study was to explore the relationship between baseline, interim and end-of-treatment PET/CT (B-PET/CT, I-PET/CT and E-PET/CT) parameters and ENKTL prognosis. Methods We searched the PubMed, EMBASE, Cochrane Library and Medline databases for eligible articles. SUVmax, MTV, and TLG on B-PET/CT, DS on I-PET/CT and DS on E-PET/CT were regarded as efficacy data. Combined hazard ratios (HRs) for progression-free survival (PFS) and overall survival (OS) were estimated using RevMan 5.3 software. Results Nine trials with a total of 535 ENKTL patients were included. SUVmax, MTV and TLG on BPET/CT were significantly associated with PFS with HRs of 2.78 (95%Cl 1.54-5.03), 3.61 (95%CI1.96-6.65) and 5.62 (95%CI1.94-16.33), respectively, and with OS with HRs of 4.78 (95%Cl 2.29-9.96), 3.20 (95%CI1.55-6.60) and 7.76 (95%Cl 1.79-33.58), respectively. For the DS on I-PET/CT, the HRs for PFS and OS were 5.15 (95%CI2.71-9.80) and 5.80 (95%Cl 2.28-14.73), respectively. Similarly, the DS on E-PET/CT was a significant predictor of PFS and OS with HRs of 3.65 (95%CI 2.13-6.26) and 3.32 (95%CI 1.79-6.15), respectively. Conclusion Our results suggest that SUVmax, MTV, TLG on B-PET/CT, DS on I-PET/CT and DS on E-PET/CT may be significant prognostic indicators for PFS and OS in ENKTL patients. Moreover, TLG tends to be superior to SUVmax and MTV on B-PET/CT for predicting survival of ENKTL patients. Therefore, response monitoring and prognostication assessments based on multiple PET/CT parameters should be considered in the management of ENKTL patients.