Predictive Value of Interim and End-of-Therapy 18F-FDG PET/CT in Patients with Follicular Lymphoma / 대한핵의학회잡지

ABSTRACT

PURPOSE: ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is the standard imaging modality for response evaluation in FDG-avid lymphoma, but the prognostic value is not established in follicular lymphoma (FL). This study investigated the prognostic value of Deauville 5-point scale (D5PS) from paired interim PET/CT (PET(Interim)) and end-of-induction therapy PET/CT (PET(EOI)) in patients with FL.METHODS: FL staging and response assessment PET/CT images from 2013 to 2015 were retrospectively reviewed. PET(Interim) was performed 3 or 4 cycles after chemotherapy and PET(EOI) after 6 or 8 cycles. D5PS scores of 1, 2, and 3 were considered as negative (−), and scores 4 and 5 were considered as positive (+). Statistical analysis was done using Cox regression analysis, Kaplan-Meier survival analysis, and the log-rank test.RESULTS: Thirty-three patients with set of baseline, interim, and end-of-induction therapy PET/CTstudies were included. Ten patients (30.3%) had progression. The median progression-free survival (PFS) was 38.8 months (range 3.5–72.7 months). On PET(Interim), 23 patients were negative and 10 were positive. On PET(EOI) scans, 29 patients were negative, and 4 were positive. On multivariate analysis, PET(EOI)(−) was associated with longer PFS. PET(Interim)(+) and PET(EOI)(+) patients had a significantly shorter PFS than PET(Interim)(−) patients (39.9 months, 95%confidence interval [CI] 23.0–56.9, versus 55.5months, 95%CI 49.7–61.2, p=0.005) and PET(EOI)(−) patients (14.2 months, 95% CI 8.5–19.8, versus 60.5 months, 95% CI 52.1–69.0, p<0.001).CONCLUSION: For patients with FL, PET(Interim) and PET(EOI) response is predictive of PFS, and PET(EOI)(+) is an independent prognostic factor for progression of FL.