Prognostic value of baseline total metabolic tumor volume (TMTV0) measured on FDG-PET/CT in patients with peripheral T-cell lymphoma (PTCL)
Menée à partir de données portant sur 108 patients atteints d'un lymphome T périphérique et ayant reçu une chimiothérapie à base d'anthracyclines (durée médiane de suivi : 23 mois), cette étude évalue l'association entre le volume tumoral métabolique total initial, mesuré au moyen d'une tomographie numérique par émission de positrons à base de fluorodésoxyglucose (18F), et la survie sans progression ou la survie globale à deux ans
Background : Most peripheral T-cell lymphoma (PTCL) patients have a poor outcome and identification of prognostic factors at diagnosis is needed.
Patients and methods : The prognostic impact of total metabolic tumor volume (TMTV0), measured on baseline 18-Fluorodeoxyglucose positron-emission tomography/computed tomography was evaluated in a retrospective study including 108 PTCL patients (27 PTCL not otherwise specified, 43 angioimmunoblastic T-cell lymphomas and 38 anaplastic large cell lymphomas). All received anthracycline-based chemotherapy. TMTV0 was computed with the 41% SUVmax threshold method and an optimal cut-off point for binary outcomes was determined and compared to others prognostic factors.
Results : With a median follow-up of 23 months, 2-year progression free survival (PFS) was 49% and 2-year overall survival (OS) was 67%. High TMTV0 was significantly associated with a worse prognosis. At 2 years, PFS was 26% in patients with a high TMTV0 (>230cm3, n=53), vs. 71% for those with a low TMTV0, (p<0.0001 HR=4), while OS was 50% vs. 80% respectively, (p=0.0005 HR=3,1). In multivariate analysis, TMTV0 was the only significant independent parameter for both PFS and OS. TMTV0, combined with PIT, discriminated even better than TMTV0 alone, patients with an adverse outcome (TMTV0>230cm3 and PIT>1, n=33,) from those with good prognosis (TMTV0≤230cm3 and PIT≤1, n=40 ) : 19% vs. 73% 2-year PFS (p<0.0001) and 43% vs. 81% 2-year OS respectively (p=0.0002). Thirty one patients (other TMTV0-PIT combinations) had an intermediate outcome, 50% 2-year PFS and 68 % 2-year OS.
Conclusion : TMTV0 appears as an independent predictor of PTCL outcome. Combined with PIT, it could identify different risk categories at diagnosis and warrants further validation as a prognostic marker.
Annals of Oncology , résumé, 2016