The relationship of volumetric parameters obtained from basal PET/CT imaging in patients diagnosed with hodgkin lymphoma, with prognostic data and chemosensitivity determined by interim PET/CT

Objective: F-18-fluorodeoxyglucose (F-18 FDG) PET/CT is currently used as the gold standard method for staging and evaluating response to treatment in patients with Hodgkin lymphoma. In this study, the value of metabolic parameters obtained from F-18 FDG PET/CT images taken for staging purposes and interim PET/CT (iPET) imaging in predicting the end-of-treatment PET (ePET) response was investigated. In addition, the relationship between the prognostic features in EORTC, GSHG and NCCN stages and IPS, and the interim PET response and the end-of-treatment PET response were evaluated. Method: 52 patients (31 men, 21 women; age range 17-74 years, mean: 43.38±16.12) with a diagnosis of Hodgkin Lymphoma, whose laboratory, pathology and treatment data could be obtained, who underwent F-18 FDG-PET/CT imaging for staging, interim evaluation and subsequent treatment response between 2016-2021 were analyzed retrospectively. Tumor parameters such as SUVmax, mean of lesion/liver SUVmax values, tumor volume (TV), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) obtained from F-18 FDG-PET/CT images taken for staging purposes before treatment and Deauville treatment response scores determined on iPET and ePET images were compared. Images after 2 cycles of ABVD were used for iPET evaluation. While scoring according to Deauville criteria; score 1 or 2: Interim and end-of-treatment response is considered as complete response in the evaluation, while score 4 or 5: Partial response if FDG uptake decreases compared to baseline in interim assessment, progressive disease if it increases compared to baseline; in the post-treatment evaluation, it was considered as treatment failure. Score 3: Interim and end-of-treatment response were evaluated as inadequate response in the evaluation. The prognostic features in EORTC, GSHG and NCCN stages and IPS were recorded and their relationship with treatment responses was evaluated. Results: 3 (5.7%) of the 52 patients included in the study were LPHL, 32 (61.5%) NSHL, 15 (28.8%) MSHL, 2 (3.8%) was LFHL type. A significant correlation was found between MTV value obtained from staging PET images and treatment responses in iPET and ePET (p=˂0.001, p=0.003, respectively). There was a positive correlation between TLG value obtained from these images and iPET and ePET treatment responses (p=0.001, p=0.006, respectively). Similar to MTV and TLG, a significant correlation was observed between total disease volume and treatment responses (p= ˂ 0.001, p=0.001, respectively). While SUVmax in the staging images of the patients showed a significant correlation with the iPET response (p=0.023), no significant correlation was found with the ePET response. There was no significant relationship between the lesion/liver SUVmax ratio and treatment responses. There was a positive correlation between LDH levels and MTV, TLG, volume values and SUVmax of the patients (p= ˂ 0.001, p= ˂ 0.001, p= ˂ 0.001, p=0.043, respectively). There was also a significant correlation between LDH levels and iPET and ePET responses (p= ˂ 0.001, p=0.002, respectively). Conclusion: SUVmax, MTV and TLG values obtained from F-18 FDG PET/CT images taken for staging of patients with Hodgkin lymphoma predict treatment response and are promising in terms of being among the prognostic markers. iPET response also stands out as a more valuable criterion than most of the prognostic markers in predicting treatment response.