18F-FDG parameters as therapy response predictors in patients with diffuse large B-cell lymphoma: A single centre experience.

Objective: The aim of this study is to determine the importance of different fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography with computed tomography (PET/CT) semi-quantitative and quantitative parameters, as well as various clinical and demographic parameters, in predicting disease outcomes and response to therapy in patients with diffuse large B-cell lymphoma (DLBCL).

Subjects and methods: The study included 64 patients diagnosed with DLBCL who underwent ¹⁸F-FDG PET/CT imaging between January 2020 and April 2023. Each patient underwent both an initial ¹⁸F-FDG PET/CT and an interim ¹⁸F-FDG PET/CT after 2 or 4 cycles of chemotherapy. The Deauville score (DS) was calculated for each patient. Progression-free survival (PFS) was defined as the time from the date of diagnosis to the first appearance of metabolic or morphological progression of pre-existing lesions and/or the appearance of new lesions detected on interim ¹⁸F-FDG PET/CT or follow-up radiological imaging, as well as in cases of death due to the underlying disease or until the end of the clinical follow-up period.

Results: Among the clinical-demographic parameters analyzed, the only significant predictive factor was the international prognostic index (IPI) score, categorized by group. Of the ¹⁸F-FDG PET/CT parameters examined, DS showed strong statistical significance in both univariate and multivariate analyses. While maximum standardized uptake value (SUVmax) and peak SUV (SUVpeak) were statistically significant in the univariate analysis. Progression-free survival was longer in patients with an IPI ≤2 and DS ≤3, compared to those with higher IPI and DS.

Conclusion: The results of this study showed that the early metabolic response to therapy assessed on the basis of interim ¹⁸F-FDG PET/CT is a significant independent predictive factor for disease outcome in patients with DLBCL.