22 | PROGNOSTIC VALUE OF BASELINE TOTAL METABOLIC TUMOR VOLUME (TMTV) AND TUMOR SPREAD (Dmax) IN ADVANCED HODGKIN LYMPHOMA: ANCILLARY STUDY OF THE AHL2011 TRIAL

Résumé fourni par la source

Purpose: Total metabolic tumor volume (TMTV) and maximum tumor distance (Dmax) measured on baseline FDG-PET to quantify tumor burden and spread, have shown strong prognostic value in lymphomas. In this ancillary study of AHL2011 trial We assessed the prognosis value of TMTV and Dmax in advanced Hodgkin lymphoma l. Methods: Eligible patients had to be enrolled in the AHL2011 trial (NCT01358747) and to have a baseline PET (PET0) and PET at 2 cycles (PET2) available for central review. Patients were 16–60 years, with a previously untreated advanced HL (Ann Arbor stage III, IV or high risk IIB) and were randomly assigned to a treatment strategy driven by PET after 2 escalated BEACOPP cycles (PET2). TMTV was calculated by summing the metabolic volumes of individual lesions segmented using the 41% SUVmax thresholding method and Dmax was defined as the maximum distance between tumoral voxels within the TMTV segmentation, normalised by body surface area. PET2 evaluations were interpreted using modified Deauville score (partial response if residual uptake > 140% liver background). X-tile analysis was used to define the optimal cutoff for survival prediction, and tested by using a training/validation method. Cox-regression models and Kaplan Meier estimates were used to analyse the TMTV and Dmax impact on progression-free survival (PFS). Results: 721 patients with a median age at diagnosis of 30 years were included and randomly assigned in a training and validation set with the same number of events. Median TMTV was 210 mL (9–2235) and median Dmax was 401 mm−1 (79–957). From a training set (n = 361) optimal cutoffs have been identified: 220 mL cut-off for TMTV (p = 0.04) and 325 mm−1 for Dmax (p = 0.01). In a validation set (n = 360), TMTV did not reach significance on PFS analysis (p = 0.18), while high Dmax was still significantly associated with a poorer PFS (p = 0.019). In the whole population, high TMTV and high Dmax were associated with a poor outcome (3 years PFS 85% vs. 91% Logrank p = 0.0012 HR = 1.98 and 85% vs. 91% HR = 2.14 Logrank p = 0.0002 respectively). PET2 positivity was also associated with a poor outcome (3 years PFS from PET2 73% vs. 91% (p < 0.0001); HR = 2.82 (95% CI: 1.78–4.46); p < 0.0001). In multivariate analysis TMTV (p < 0.05), Dmax (p < 0.025) and PET2 (p = 0.0002) were independent factors predicting PFS overcoming the IPS prognosis value. By combining TMTV, Dmax and PET2, 3 groups could be identified: patients with either [3 factors: high-TMTV, high-Dmax and PET2+ (High risk group: n = 29; 4%)], or [one or two of these factors (n = 408; 57%)], or [0 factor: low-TMTV low Dmax and PET2- (n = 284; 39%)] had a 69%, 86%, 95% 3 years-PFS respectively (p < 0.0001) (Figure 1). Conclusions: TMTV, Dmax and PET2 are independent predictors of young advanced HL patients outcomes allowing to identify 3 subsets of HL patients with significantly different outcomes that may help clinicians to better tailor therapy. Keywords: PET-CT; Hodgkin lymphoma No potential sources of conflict of interest.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.