Prognostic value of metabolic parameters in baseline 18F-FDG PET/CT for pediatric lymphoblastic lymphoma

Abstract

Purpose: This retrospective study aimed to evaluate the prognostic value of metabolic parameters in baseline fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) for pediatric lymphoblastic lymphoma (LBL). Method: Thirty patients with LBL who underwent baseline 18F-FDG PET/CT from April 2013 to November 2018 were enrolled. Their metabolic parameters including maximum standardized uptake value (SUVmax), total metabolic tumor volume (TMTV), and total lesion glycolysis (TLG) were measured and compared with those from different clinical characteristic groups. Event-free survival (EFS) and overall survival (OS) curves were constructed using the Kaplan-Meier method and compared with the log-rank test. Results: The patients with stage IV had higher TMTV than stage III (mean 580.66cm³ vs. 176.52cm³; p=0.031). No statistical significance in SUVmax and TLG was observed between patients with stages III and IV (p=0.061; p=0.291). After a median follow-up of 41.5 months (range of 1-86 months), the patients with a low TMTV (<242.91cm3) had better 3-year EFS rate compared with those with a high TMTV (88.9% vs. 56.3%; p=0.036). However, SUVmax and TLG were not predictive of EFS(p=0.874; p=0.152). Conclusions: TMTV may be a potential PET/CT metabolic parameter for predicting the prognosis of pediatric lymphoblastic lymphoma. A high TMTV indicates a poor outcome. However, SUVmax and TLG are not related to the prognosis of pediatric lymphoblastic lymphoma.

The Utility of Metabolic Parameters on Baseline F-18 FDG PET/CT in Predicting Treatment Response and Survival in Paediatric and Adolescent Hodgkin Lymphoma

“…However, tMTV was not found to be an independent prognostic factor for PFS [2]. This contrasts with the findings of Yang et al and Mathew et al, who recently demonstrated the utility of baseline tMTV as a prognostic marker in paediatric lymphoblastic lymphoma and paediatric anaplastic large cell lymphoma, respectively [6,8]. On the other hand, Chen et al found that baseline tMTV as well as TLG are both strong independent prognostic factors for paediatric NHL, outperforming other clinical-pathological risk factors (including serum LDH and bone marrow involvement on biopsy) in predicting survival [10].…”

“…In contrast, none of the metabolic parameters in question (SUV max , MTV, and TLG) featured as predictors for either PFS or OS, and only MTV was predictive of treatment response. Although the prognostic value of SUV max has been demonstrated in multiple studies, its reliability may be compromised by a host of factors, including but not limited to blood glucose levels, body weight, administered FDG dose (including the effects of extravasation), residual activity left in the syringe, decay of injected dose, uptake time, the presence of partial volume effects, and reconstruction parameters [2,[6][7][8][9]. In addition, SUV max is only measured by the highest image pixel in the tumor region and therefore does not show the metabolic activity of the entire tumor [17].…”

“…MTV is the sum of voxels with an increased SUV inside the tumor lesion and represents the volume of viable tumor cells (the tumor volume with increased metabolism) [6,17]. TLG is the product of the MTV and SUV mean of the lesion and therefore reflects tumor metabolic activity and volume [8]. It follows that tMTV or WB-MTV (total or whole-body MTV) is the sum of the metabolic volumes of all lesions, whereas WB-TLG is the sum of all lesion TLGs.…”

“…There is also a need to establish the value of F-18 FDG PET/CT in response evaluation of paediatric non-Hodgkin lymphoma, which (in contrast to Hodgkin lymphoma) is not well-defined [3,8,[10][11][12]. Overall, there is a need to improve the response criteria to increase the prognostic value of PET in non-Hodgkin lymphoma.…”

“…However, there is a paucity of data regarding the value of various metabolic parameters (namely whole-body metabolic tumor volume, [WB-MTV or tMTV] and total lesion glycolysis [TLG]) on baseline F-18 FDG PET/CT for riskstratification and prediction of OS and PFS. The most well-studied metabolic parameter, the maximum standard uptake value (SUV max ), is not always reproducible as its measurement is influenced by a number of different factors, and it is therefore not always reliable for prognostication [2,[6][7][8][9]. Metabolic volumetric parameters, on the other hand, give an indication of the whole-body tumor burden, and have recently been proposed as a valuable tool for prognostication.…”