Prognostic efficiency of interim 18F-FDG PET/CT in patients with diffuse large B-cell lymphoma / 中华核医学与分子影像杂志

ABSTRACT

Objective To explore whether the prognostic efficiency of international prognostic index (IPI) can be further improved by interim 18F-fluorodeoxyglucose (FDG) PET/CT.Methods A total of 185 patients (116 males,69 females;average age 49 years) with pathologically confirmed diffuse large Bcell lymphoma (DLBCL) from January 2004 to January 2014 were enrolled in this retrospective study.The risk was classified by IPI (0-2 was considered as low risk,3-5 was considered as high risk) and all patients underwent 18F-FDG PET/CT scan before and after 4 cycles of immunochemotherapy.Based on interim 18 F-FDG PET/CT imaging,5-point Deauville score was used to reclassify DLBCL patient into negative group and positive group,and the interpretations were evaluated for 2-year progression-free survival (PFS) and overall survival (OS) rates.Kaplan-Meier analysis,log-rank test and Cox regression were used for data analysis.Results With a median follow-up of 27 (2-146) months,the 2-year PFS and OS rates were 60％(111/185) and 81％(150/185),respectively.A total of 114 patients were included in the low-risk group and 71 patients were in the high-risk group.Both 2-year PFS rates and OS rates between the 2 groups were statistically different72％(82/114) vs 37％(26/71),x2=20.86,P＜0.01;90％(103/114) vs 63％(45/71),x2=13.39,P＜0.01.The interim PET/CT showed 113 patients with negative results and 72 patients with positive results,whose 2-year PFS rates and OS rates were also statistically different82％ (93/113) vs 24％(17/72),x2 =66.66,P＜0.01;90％(102/113) vs 51％(37/72),x2 =33.11,P＜0.01.In the low-risk group,85 patients were PET-negative and 29 patients were PET-positive.The 2-year PFS rates were 88％ (75/85) and 31％(9/29),respectively (x2 =35.52,P＜0.01).The 2-year OS rates were 96％ (82/85) and 66％(19/29),respectively (x2 =11.88,P＜0.01).In the high-risk group,28 patients were PET-negative and 43 patients were PET-positive.The 2-year PFS and OS rates were 64％(18/28) vs 19％(8/43;x2 =17.33,P＜0.01) and 86％(24/28) vs 49％(21/43;x2=9.95,P＜0.01),respectively.Conclusions Both IPI and interim 18F-FDG PET/CT have the prognostic value for patients with DLBCL.Interim 18F-FDG PET/CT can improve the prognostic efficiency of IPI.