Predictive value of baseline metabolic tumor volume in early-stage favorable Hodgkin Lymphoma - Data from the prospective, multicenter phase III HD16 trial

Abstract

Background: ¹⁸F -fluorodeoxyglucose (FDG) positron emission tomography (PET) plays an important role in the staging and response assessment of lymphoma patients. Our aim was to explore the predictive relevance of metabolic tumor volume (MTV) and total lesion glycolysis (TLG) in patients with early stage Hodgkin lymphoma treated within the German Hodgkin Study Group HD16 trial.

Methods: ¹⁸F-FDG PET/CT images were available for MTV and TLG analysis in 107 cases from the HD16 trial. We calculated MTV and TLG using three different threshold methods (SUV_4.0, SUV_41% and SUV_140%L), and then performed receiver-operating-characteristic analysis to assess the predictive impact of these parameters in predicting an adequate therapy response with PET negativity after 2 cycles of chemotherapy.

Results: All three threshold methods analyzed for MTV and TLG calculation showed a positive correlation with the PET response after 2 cycles chemotherapy. The largest area under the curve (AUC) was observed using the fixed threshold of SUV_4.0 for MTV- calculation (AUC 0.69 [95% CI 0.55-0.83]) and for TLG-calculation (AUC 0.69 [0.55-0.82]). The calculations for MTV and TLG with a relative threshold showed a lower AUC: using SUV_140%L AUCs of 0.66 [0.53-0.80] for MTV and 0.67 for TLG [0.54-0.81]) were observed, while with SUV_41% an AUC of 0.61 [0.45-0.76] for MTV, and an AUC 0.64 [0.49-0.80]) for TLG were seen.

Conclusions: MTV and TLG do have a predictive value after two cycles ABVD in early stage Hodgkin lymphoma, particularly when using the fixed threshold of SUV_4.0 for MTV and TLG calculation.

Trial registration: ClinicalTrials.gov NCT00736320 .

Keywords: FDG PET; Hodgkin lymphoma; Metabolic tumor volume; Response prediction.

Fig. 1

Flow chart. 1150 patients included in the HD16 trial. Baseline ¹⁸F-FDG PET was centrally reviewed in 107 patients with quantitative analyses. Abbreviations: ITT, intention to treat. HL, Hodgkin lymphoma. MTV, metabolic tumor volume. TLG, total lesion glycolysis

Fig. 2

Histograms of MTV distribution assessed by different thresholding methods. MTV was obtained using the following thresholds: 41% of the SUV_max within the respective lymphoma site (MTV_41%), a fixed SUV of 4.0 (MTV_4.0), and 140% of the SUV_max of liver background MTV_140%L. Abbreviations: MTV, metabolic tumor volume

Fig. 3

Histograms of TLG distribution assessed by different thresholding methods. TLG was obtained using the following thresholds: 41% of the SUV_max within the respective lymphoma site (TLG_41%), a fixed SUV of 4.0 (TLG_4.0), and 140% of the SUV_max of liver background (TLG_140%L). Abbreviations: TLG, total lesion glycolysis

Fig. 4

ROC curves of MTV distribution assessed by different thresholding methods for PET response after two cycles of ABVD (16/107 = 15% PET-2-positive patients with Deauville score 4). MTV was obtained using the following thresholds: 41% of the SUV_max within the respective lymphoma site (MTV_41%) a fixed SUV of 4.0 (MTV4.0) and 140% of liver background (MTV_140%L). Abbreviations: MTV, metabolic tumor volume. AUC, area under the curve

Fig. 5

ROC curves of TLG distribution assessed by different thresholding methods for PET response after two cycles of ABVD (16/107 = 15% PET-2-positive patients with Deauville score 4). TLG was obtained using the following thresholds: 41% of the SUV_max within the respective lymphoma site (TLG_41%) a fixed SUV of 4.0 (TLG4.0) and 140% of the SUV_max of liver background (TLG_140%L). Abbreviations: TLG, total lesion glycolysis. AUC, area under the curve