Ability of final PET/CT to predict response to first-line treatment in real patients with classical Hodgkin lymphoma.

Up to 25% of patients with classical Hodgkin lymphoma (cHL) and a negative interim PET/CT will progress. Unfortunately, there are few published studies on the predictive value of PET/CT performed after finishing treatment. The objective of our study was to assess the role of the final PET/CT (fPET/CT) in predicting progression in a retrospective series of patients treated in the last 10 years with a homogeneous protocol (ABVD + / - radiotherapy). We reviewed a cohort of 227 patients with newly diagnosed cHL. fPET/CT was performed on 212 patients (93%). In patients with a positive fPET, progression-free survival at 60 months was 17% (94% if fPET was negative, p = 0.000). The positive and negative predictive values for the fPET were 76% and 94%, respectively (Fisher's exact test, p = 0.000). In the subgroup of patients with advanced-stage cHL, progression-free survival at 60 months was 91% with negative fPET and 0% with positive fPET (p = 0.000). However, fPET was negative in 19 of the 29 patients with a positive interim PET/CT (only 2 showed progression). In conclusion, fPET is a useful tool to predict treatment failure in patients with newly diagnosed cHL, especially advanced-stage disease.