Abstract:
Objective To construct prognostic nomogram models of 18F-fluorodeoxyglucose (FDG) PET-based metabolic and clinical parameters and validate their importance to survival prediction of patients with diffuse large B-cell lymphoma (DLBCL).
Methods 18F-FDG PET image and clinical characteristics of 383 patients with DLBCL who received no treatments and underwent histopathology in the Affiliated Drum Tower Hospital, Medical School of Nanjing University, and the First Affiliated Hospital of Nanjing Medical University from March 2011 to November 2019 were retrospectively analyzed. The patients included 204 males and 179 females, aged 19–93(47.3±14.9) years old. The patients were randomly allocated as the training group (n=268) and validation group (n=115) at a 7∶3 ratio. The total metabolic tumor volume (TMTV) and total lesion glycolysis (TLG) were computed. Kaplan-Meier survival analysis, univariate and multivariate Cox proportional hazard regression models were used to evaluate progression-free survival (PFS) and overall survival (OS). The models were construct, and performance was assessed and validated with regard to calibration, discrimination, and clinical usefulness by calibration curve, concordance index (C-index), and decision curve analysis (DCA).
Results Univariate analysis indicated that age, lactate dehydrogenase (LDH) level, Eastern Cooperative Oncology Group performance status (ECOG PS) score, Ann Abor stage, bulky, TMTV, and TLG were factors for predicting PFS in the training group (HR=1.670–3.277, all P<0.05). Age, LDH level, B symptoms, ECOG PS score, Ann Abor stage, bulky, TMTV, and TLG were factors for predicting OS in the training group (HR=1.661–4.193, all P<0.05). Multivariate Cox regression analyses showed that age, LDH level, Ann Arbor stage, and TLG were independent predictors of PFS and OS of DLBCL patients in the training group (HR=1.589–3.367, all P<0.05). Calibration curves showed that the models had good consistency for survival. The C-index showed that the models exhibited significant prognostic superiority in training and validation group (PFS: 0.724 vs. 0.762; OS: 0.749 vs. 0.753). Clicinal DCA showed that the prediction model could bring more clinical usefulness to patients.
Conclusion 18F-FDG PET metabolic (TLG) and clinical (age, LDH level, and Ann Abor stage) parameters can successfully predict patient prognosis, which may promote precision medicine.