Prognostic role of baseline ¹⁸F‐FDG PET/CT parameters in MALT lymphoma

Abstract

Mucosa‐associated lymphoid tissue (MALT) lymphoma is an indolent lymphoma with good prognosis and variable fluorine‐18 fluorodeoxyglucose (18F‐FDG) avidity. Many possible prognostic factors have been investigated with controversial results, but the possible prognostic role of 18F‐FDG positron emission tomography/computed tomography (PET/CT) remains unclear. Our aim was to evaluate the prognostic impact of qualitative and semiquantitative baseline PET/CT parameters on outcome of MALT lymphoma. We retrospectively enrolled 161 patients with histologically confirmed MALT lymphoma who underwent 18F‐FDG PET/CT before any treatment. PET images were qualitatively and semiquantitatively analyzed by measuring the maximum standardized uptake value body weight (SUVbw), lean body mass (SUVlbm), body surface area (SUVbsa), metabolic tumor volume (MTV), and total lesion glycolysis (TLG). The Kaplan‐Meier method was used to estimate the progression‐free survival (PFS) and overall survival (OS) times. Cox regression models were performed to determine the relation between PET/CT features and OS and PFS. Ninety‐eight patients had positive 18F‐FDG PET/CT showing 18F‐FDG uptake (mean SUVbw, 10.1; SUVlbm, 7.2; SUVbsa, 2.7; MTV, 88.8; and TLG, 526); the remaining 63 were not 18F‐FDG avid. 18F‐FDG avidity was significantly correlated with tumor size and Ki‐67 score. Relapse/progression of disease occurred in 47 patients with an average time of 40.2 months; death occurred in 12 patients with an average of 59 months. At a median follow‐up of 62 months, median PFS and OS were 52 and 62 months, respectively. Advanced tumor stage and extragastric site were demonstrated to be independent prognostic factors for PFS, while only tumor stage for OS. Instead, PET/CT parameters were not related to survival, despite positive correlation at univariate analysis between MTV and TLG with PFS and positive PET/CT with PFS and OS. In conclusion, a 61% rate of PET avidity in biopsy‐confirmed MALT lymphoma was found, and it was correlated with tumor size and Ki‐67 score. Only tumor stage and localization were independently correlated with PFS and OS.

FDG PET/CT as a diagnostic and prognostic tool for the evaluation of marginal zone lymphoma

“…This is in accordance with a recent retrospective analysis of 161 PET/CT − BMB− 19 (26) patients with MALT lymphoma, of whom 98 had positive FDG uptake, which demonstrated that baseline positive FDG uptake was not associated with PFS or OS. 25 Determining BMI may have an effect on prognosis of MZL patients because it may influence both stage and extranodal involvement, both comprising the IPI. The reported incidence of BMI in SMZL is 70% to 100%, and for the other subtypes of MZL, 30% to 40%.…”

The Role of 2-[18F]-FDG PET/CT in Detecting Richter Transformation in Chronic Lymphocytic Leukemia: A Systematic Review

“…Subsequently, other PET parameters related to the metabolic volumes (MTV and TLG) were derived and were defined as parameters that represent the morphological and metabolic features in the same feature [37]. In the literature, other manuscripts investigated the potential role of MTV and TLG in lymphoproliferative diseases, especially in the prognostic field [38][39][40][41], but in CLL patients only two studies [23,26] analyzed these factors, reporting controversial results. For Pontoizeau et al [23], baseline MTV was a predictor of overall survival in RT, while in the other paper [26], MTV and TLG were not related to survival.…”

Prognostic significance of interim PET/CT response for the treatment of advanced-stage marginal zone lymphoma in the post-rituximab era

“…DS and SUVmax were not centrally determined, although the PET/CT image was reviewed by experienced physicians at each institution. The SUV reliability can be influenced by many factors such as blood glucose level, technological characteristics, partial volume effect, injected dose and decay of radiotracer 31 . However, recent studies suggest that PET/CT response assessments using DS have small interobserver differences 32,33 .…”