Prognostic value of interim ¹⁸F-FDG PET/CT in adult follicular lymphoma treated with R-CHOP

The prognostic value of interim ¹⁸F-FDG PET/CT (I-PET) for follicular lymphoma (FL) is controversial, and may be related to the lack of strict standards in terms of age, chemotherapy regimen, and evaluation criteria in previous studies. This study aimed to investigate the prognostic value of I-PET in adult FL patients treated with R-CHOP.

I-PET was performed in 30 adult FL patients after treatment with 3-5 cycles of R-CHOP. PET/CT images were assessed using the Deauville 5-point scale (D-5PS) criteria. Baseline PET/CT (B-PET) was performed in 24 of the patients with FL before treatment. The PET/CT image parameters, such as the SUVmax, TLG, and tMTV, were recorded. The prognostic values of sex, age, grade, Ann Arbor stage, LDH level, and I-PET were evaluated.

Kaplan-Meier analysis and Cox regression showed that sex, age, grade, Ann Arbor stage, LDH, and I-PET using the D-5PS criteria could not predict the PFS of adult patients with FL treated with R-CHOP (P>0.05). ROC curve analysis evaluated the predictive values of SUVmax, TLG, and tMTV in B-PET and I-PET and showed that none of them was predictive of PFS in adult FL patients (P>0.05). However, the variation in SUVmax (∆SUVmax) was predictive of PFS in adult FL patients (AUC=0.83, P=0.040), and the cutoff threshold was 4.85.

I-PET using the D-5PS criteria cannot predict the PFS of adult FL patients treated with R-CHOP. However, the ∆SUVmax between B-PET and I-PET is applicable for the prognosis of adult patients with FL.