[18F] Positron emission tomography response after rituximab-containing induction therapy in follicular lymphoma is an independent predictor of survival after adjustment for FLIPI in academic and community-based practice
Positron emission tomography (PET) after induction therapy in follicular lymphoma (FL) is predictive of survival in clinical trials. We describe use of PET and computed tomography (CT) after rituximab-based induction therapy in FL patients followed by the National LymphoCare Study and explore the association between imaging response assessment and survival. Among 1289 patients, imaging consisted of: PET ± CT (35%), CT alone (42%), other/no imaging (24%). Median follow-up was 7.6 years. In unadjusted analyses, positive PET ± CT and CT were prognostic of inferior OS (HR 1.78; 95% CI: 1.16-2.72 and HR 1.61, 95% CI: 1.13-2.29, respectively) and PFS (HR 1.63, 95% CI: 1.21-2.20 and HR 1.45, 95% CI: 1.12-1.89, respectively). Adjusting for FL International Prognostic Index, PET remained predictive of OS (HR 1.54, 95% CI: 1.01-2.36) and PFS (HR 1.54, 95% CI: 1.14-2.07). Residual disease via PET in FL is prognostic of survival in clinical practice.