Patterns of response and relapse in primary CNS lymphomas after first-line chemotherapy: imaging analysis of the ANOCEF-GOELAMS prospective randomized trial

Emeline Tabouret (1, 2, 3) , Caroline Houillier (3) , Nadine Martin-Duverneuil (3) , Marie Blonski (4) , Carole Soussain (5) , Herve Ghesquières (6) , Roch Houot (7) , Delphine Larrieu (8) , Pierre Soubeyran (9) , Remy Gressin (10) , Emmanuel Gyan (11) , Olivier Chinot (2, 1) , Luc Taillandier (4) , Sylvain Choquet (3) , Agusti Alentorn (12, 3) , Delphine Leclercq (3) , Antonio Omuro (13) , Marie-Laure Tanguy (3) , Khe Hoang-Xuan (3)

1 TIMONE - Hôpital de la Timone [CHU - APHM]
2 CRO2 - Centre de Recherches en Oncologie biologique et Oncopharmacologie
3 CHU Pitié-Salpêtrière [AP-HP]
4 CHU Nancy - Centre Hospitalier Universitaire de Nancy
5 CRLCC René Huguenin - CRLCC René Huguenin
6 CHLS - Centre Hospitalier Lyon Sud [CHU - HCL]
7 Hôpital Sud [CHU Rennes]
8 CHU de Poitiers [La Milétrie] - Centre hospitalier universitaire de Poitiers = Poitiers University Hospital
9 Institut Bergonié [Bordeaux]
10 CHUGA - Centre Hospitalier Universitaire [CHU Grenoble]
11 CHU Trousseau [Tours]
12 ICM - Institut du Cerveau et de la Moëlle Epinière = Brain and Spine Institute
13 MSKCC - Memorial Sloan Kettering Cancer Center

Background: Our aim was to review MRI characteristics of patients with primary CNS lymphoma (PCNSL) enrolled in a randomized phase II trial and to evaluate their potential prognostic value and patterns of relapse, including T2 fluid attenuated inversion recovery (FLAIR) MRI abnormalities. Methods: Neuroimaging findings in 85 patients with PCNSL enrolled in a prospective trial were reviewed blinded to outcomes. MRI characteristics and responses according to International PCNSL Collaborative Group (IPCG) criteria were correlated with progression-free survival (PFS) and overall survival (OS). Results: Multivariate analysis showed that objective response at 2 months (P < .001) and at end of treatment (P = .015) were predictors of prolonged OS. Infratentorial location (P = .008) and large (>11.4 cm3) enhancing tumor volume (P = .006) were associated with poor OS and PFS, respectively. Ratio of change in product of largest diameters at early MRI evaluation but not timing of complete response achievement (early vs delayed) was prognostic for OS. Sixty-nine patients relapsed. Relapse in the brain (n = 52) involved an initial enhancing site, a different site, or both in 46%, 40%, and 14% of patients, respectively. At baseline, non-enhancing T2-FLAIR hypersignal lesions distant from the enhancing tumor site were detected in 18 patients. These lesions markedly decreased (>50%) in 16 patients after chemotherapy, supporting their neoplastic nature. Of these patients, 10/18 relapsed, half (n = 5) in the initially non-enhancing T2-FLAIR lesions. Conclusions: Baseline tumor size and infratentorial localization are of prognostic value in PCNSL. Our findings provide evidence that non-enhancing FLAIR abnormalities may add to overall tumor burden, suggesting that response criteria should be refined to incorporate evaluation of T2-weighted/FLAIR sequences.

Mots clés: T2-weighted/FLAIR sequences; magnetic resonance imaging; primary CNS lymphoma; prognostic factor; response criteria

Domaines: Médecine humaine et pathologie

Emeline Tabouret, Caroline Houillier, Nadine Martin-Duverneuil, Marie Blonski, Carole Soussain, et al.. Patterns of response and relapse in primary CNS lymphomas after first-line chemotherapy: imaging analysis of the ANOCEF-GOELAMS prospective randomized trial. Neuro-Oncology, 2016, 19 (3), pp.now238. ⟨10.1093/neuonc/now238⟩. ⟨hal-04406451⟩