November 12, 2018
Paper of the Month November 2018
This month we feature a LANCET Oncology paper published online on October 8, 2018, evaluating the prognostic value of metabolic response assessed by PET and morphologic response assessed by CT after first-line immunochemotherapy in a large population of patients with follicular lymphoma.
Enjoy the reading,
the BELNUC Board
« Prognostic value of end-of-induction PET response after first-line immunochemotherapy for follicular lymphoma (GALLIUM): secondary analysis of a randomised, phase 3 trial »
2018, Judith Trotman et al., Lancet Oncology
GALLIUM is an open-label, parallel-group randomised, phase 3 trial, having previously shown that patients with CD20-positive follicular lymphoma have a longer progression-free survival (PFS) after first-line immunochemotherapy with obinutuzumab than with rituximab.
The present paper focuses on a secondary analysis of patients from the GALLIUM study in whom a baseline and an end-of-induction PET were performed (>500 patients).
CT and PET were prospectively analysed by investigators and an independent review committee (IRC) applying International Harmonisation Project (IHP) 2007 response criteria. After the international guidelines were updated, IRC members retrospectively analysed the PET exams applying current Lugano 2014 response criteria (which incorporates the ordinal Deauville 5-point scale). IRC members were blinded to clinical outcome when assessing response.
The proportion of patients achieving a complete metabolic response as per PET assessment was more than two-times higher than the proportion achieving complete response as determined by CT.
Metabolic response assessment with Lugano 2014 criteria was a better predictive tool for PFS than PET or CT analysis with IPH 2007 criteria. Metabolic response assessment with Lugano 2014 criteria was also predictive of overall survival and, finally, demonstrated a five-time increase in risk of progression and early death in patients who did not achieve a complete metabolic remission.
Evidence from this study suggests PET as a prognostic tool and a better imaging modality than contrast-enhanced CT after first-line therapy in patients with follicular lymphoma. The data also support the use of PET assessment according to Lugano 2014 current guidelines.