Value of ¹⁸F-FDG PET/CT for prognostic stratification in patients with primary intestinal diffuse large B cell lymphoma treated with an R-CHOP-like regimen

The prognostic value of ¹⁸F-FDG PET/CT for primary intestinal diffuse large B-cell lymphoma (PI-DLBCL) patients has not been determined. This prompted us to explore the value of ¹⁸F-FDG PET/CT for prognostic stratification in patients with PI-DLBCL treated with an R-CHOP-like regimen.

Seventy-three PI-DLBCL patients who underwent baseline PET/CT between January 2010 and May 2019 were included in this retrospective study. Total metabolic tumor volume (TMTV) and total lesion glycolysis (TLG) were computed using the 41% SUV_max thresholding method. Progression-free survival (PFS) and overall survival (OS) were used as endpoints to evaluate prognosis.

During the follow-up period of 3–117 months (29.0 ± 25.5 months), high TLG, non-germinal center B-cell-like (non-GCB) and high National Comprehensive Cancer Network International Prognostic Index (NCCN-IPI) were significantly associated with inferior PFS and OS. TLG, cell-of-origin and NCCN-IPI were independent predictors of PFS, and both TLG and NCCN-IPI were independent predictors of OS. The grading system was based on the number of risk factors (high TLG, non-GCB, high NCCN-IPI) and patients were divided into 4 risk groups (PFS: χ² = 33.858, P < 0.001; OS: χ² = 29.435, P < 0.001): low-risk group (none of the 3 risk factors, 18 patients); low-intermediate risk group (1 risk factor, 24 patients); high-intermediate risk group (2 risk factors, 16 patients); and high-risk group (all 3 risk factors, 15 patients).

High TLG, non-GCB and high NCCN-IPI can identify a subset of PI-DLBCL patients with inferior survival outcomes. Furthermore, the grading system can identify PI-DLBCL patient groups with markedly different prognoses, which might contribute to the adjustment of the therapeutic regime.