Introduction: Traditional prognostic indices, while widely used, exhibit limitations in comprehensively delineating the clinical heterogeneity of follicular lymphoma (FL). Positron emission tomography combined with computed tomography (PET/CT) during upfront treatment is investigated as a potential method for refining prognostication and informing therapeutic decision-making in FL. This study was designed to evaluate the prognostic value of interim PET/CT imaging in newly diagnosed FL patients undergoing front line therapy.

Methods: This retrospective, single-center evaluation comprised 114 treatment-naive FL patients who had PET/CT imaging, performed after 3-4 cycles of front line therapy between 2009 and mid-2025. Notably, the utilization of interim PET/CT scans was not uniformly adopted as a standard practice during the investigated period, this study was granted approval by the Regional and Institutional Research Ethics Committee at the University of Debrecen. The primary outcome measure was progression-free survival (PFS). The prognostic significance of positive PET/CT results performed after 3-4 cycles of treatment, SUVmax values and Deauville scores were assessed in conjunction with other clinical parameters. A Deauville score of 1-3 was considered a negative, while a score of 4-5 was considered a positive examination. Patients received chemo immunotherapy if treatment initiation was indicated according to GELF criteria, anti-CD20 monoclonal antibody and rituximab, cyclophosphamide, vincristine, prednisolone or bendamustine or cyclophosphamide, doxorubicin, vincristine, prednisolone chemotherapy combination.

Results: The median age was 54 years at diagnosis, and median follow up was 45 months. Thirty-two patients (28.1%) presented with positive interim PET/CT results. FL patients who had a Deauville score of 1-3 had significantly superior PFS compared to those, with Deauville score 4-5 (median PFS not reached vs. 14 months, p<0.0001) at the interim time point. In particular, those FL patients who demonstrated a SUVmax value of more than 3.315, determined by a receiver operating characteristic (ROC) analysis, at the interim PET/CT had a significantly reduced PFS as compared to those with lower values (median PFS 42 months vs. not reached, p<0.0001). We did not observe a survival correlation with SUVmax change and/ or ratio of the baseline and interim examination.Discussion: In conclusion, our data may strengthen the otherwise unclear prognostic value of interim PET/CT in FL. However, these findings are tempered by the study's retrospective design, single institution data collection, and limited sample size. Nevertheless, the most effective PET/CT measurement remains a topic of discussion. Additional studies are warranted to confirm our observations and to investigate individualized treatment approaches informed by interim PET/CT findings.

This content is only available as a PDF.
2025
Sign in via your Institution