Prognostic Values of Baseline 18F-FDG PETCT in Patients with Peripheral T-Cell Lymphoma

Abstract EN

Purpose.

In the present study, we aimed to investigate whether the metabolic parameters on baseline 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) could be used to predict prognosis in peripheral T-cell lymphomas (PTCL).

Methods.

A total of 51 nodal PTCL patients who underwent baseline 18F-FDG PET/CT were retrospectively evaluated in the present study.

Total metabolic tumor volume (TMTV), total lesion glycolysis (TLG), and maximum standardized uptake value (SUVmax) were also assessed.

Besides, the National Comprehensive Cancer Network International Prognostic Index (NCCN-IPI) was also included.

Log-rank test and Cox regression analysis were used to evaluate progression-free survival (PFS) and overall survival (OS).

Results.

The median follow-up was 18 months.

Patients with low TLG, TMTV, and SUVmax levels had a significantly better clinical outcome than those with high TLG, TMTV, and SUVmax levels.

The 2-year PFS rates of the high- and low-TMTV groups were 34.62% and 80%, respectively (p<0.001), whereas the corresponding 2-year OS rates were 46.15% and 84.00%, respectively (p<0.001).

The 2-year PFS rates of the high- and low-TLG groups were 29.63% and 87.50%, respectively (p<0.001), whereas the corresponding 2-year OS rates were 40.74% and 91.67%, respectively (p<0.001).

In multivariate analysis, TLG and TMTV were independent prognostic factors of both PFS (HR 11.562, 95% CI 3.218-41.542, p<0.001 and HR 7.061, 95% CI 2.464-20.229, p<0.001, respectively) and OS (HR 11.609, 95% CI 2.595-51.930, p=0.001 and HR 5.026, 95% CI 1.538-16.421, p=0.008, respectively).

Moreover, SUVmax and NCCN-IPI scores were also independent predictors of OS (HR 3.161, 95% CI 1.197-8.346, p=0.020 and HR 3.112, 95% CI 1.109-8.732, p=0.031, in TMTV multivariate models).

Combination of TMTV and NCCN-IPI scores stratified the patients into three risk groups for PFS (p=0.002) and OS (p<0.001) as follows: high-risk group with TMTV>62.405 cm3 and NCCN-IPI score of 4-8 (2-year PFS and OS were both 20%, n=10), intermediate-risk group with TMTV>62.405 or NCCN-IPI score of 4-8 (2-year PFS and OS were 52.4% and 66.7%, respectively, n=21), and low-risk group with TMTV≤62.405 cm3 and NCCN-IPI score of 0-3 (2-year PFS and OS were 80% and 85%, respectively, n=20).

Conclusions.

Baseline TMTV and TLG were independent predictors of PFS and OS in PTCL patients, and SUVmax and NCCN-IPI scores were also independent predictors of OS.

Moreover, the combination of TMTV and NCCN-IPI scores improved patient risk-stratification at the initial stage and might contribute to the adjustment of the therapeutic regime.

This trial is registered with ChiCTR1900025526.