Tumor necrosis and ascites on baseline 18F-FDG PET/CT as independent prognostic imaging markers for double/triple-hit lymphoma.

Abstract

Objective: Double and triple hit lymphoma (DHL/THL) is a rare genetic subtype of diffuse large B-cell lymphoma (DLBCL) characterized by extremely aggressive behavior. Tumor necrosis and ascites are also commonly associated with a poor prognosis. This study aimed to assess the potential prognostic markers on baseline fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) in DHL/THL patients.

Subjects and methods: A total of 36 DHL/THL patients, with myelocytomatosis (MYC) and B-cell lymphoma 2 (BCL2) and/or B-cell lymphoma 6 (BCL6) rearrangements from 3 independent medical centers, were retrospectively studied. These patients all underwent baseline ¹⁸F-FDG PET/CT scans between November 2012 and February 2024. Presence of tumor necrosis and ascites were visually assessed at PET and CT, as necrosis^PET and ascites^CT, respectively. Survival analyses were performed using Cox regression and Kaplan-Meier methods. Progression-free survival (PFS) and overall survival (OS) were used as endpoints. Time-dependent receiver operating characteristics (ROC) curves were used to assess the predictive power of necrosis^PET and ascites^CT.

Results: Of the 36 patients, 14 experienced recurrence, and 12 died during the follow-up period. Multivariate analysis revealed that necrosis^PET (hazard ratio [HR]=5.272, P=0.009; HR=5.363, P=0.026) and ascites^CT (HR=5.558, P=0.008; HR=7.384, P=0.020) were independently prognostic factors for PFS and OS. Time-dependent ROC analysis showed that necrosis^PET and ascites^CT had good performance in predicting PFS (accuracy: 0.671-0.758) and OS (accuracy: 0.686-0.769) occurring within 1-4 years. The risk model, incorporating necrosis^PET and ascites^CT, can effectively stratify patients for PFS (χ²=11.804, P=0.003 and χ²=15.754, P<0.001, respectively) and OS (χ²=20.599, P<0.001 and χ²=18.369, P<0.001, respectively) in subgroup analyses of patients treated with R-CHOP and intensive regimens, respectively.

Conclusion: Necrosis^PET and ascites^CT independently predict survival in DHL/THL patients and may improve risk stratification, potentially guiding personalized therapeutic strategies.