Outcome of Primary Mediastinal Large B-Cell Lymphoma Using R-CHOP: Impact of a PET-Adapted Approach

Outcome of Primary Mediastinal Large B-Cell Lymphoma Using R-CHOP: Impact of a PET-Adapted Approach

Abstract

Primary mediastinal large B-cell lymphoma remains a challenging entity to manage.  PET/CT guided consolidative therapy guidelines remain to be established.  On December 10, 2020, investigators reported in the general Blood, the results of PET/CT guided consolidative radiotherapy.  Patients over the age of 18, with primary mediastinal B-cell lymphoma, who are treated with curative intent rituximab-based chemotherapy for enrolled in the study.  R-CHOP was the preferred chemotherapy regimen. End of treatment PET scan was used to guide radiotherapy and only patients with PET positive scan received radiotherapy. 

Prior to the year 2005, patients were routinely given R-CHOP plus radiotherapy which was defined as radiotherapy error.  Beginning in 2005, end of treatment PET scan was used to guide radiotherapy and only list patients with PET positive disease received radiotherapy.  This was known as the PET era.  A total of 159 patients were identified in the study.  94% were treated with R-CHOP and 44% received radiotherapy, 78% in the radiotherapy rea and 28% in the PET area.  The 5-year time to progression in overall survival for the entire patient population was 80% and 89%, respectively.  This was similar across treatment eras. 

Overall, 10% of patients had refractory disease.  113 patients had end of treatment PET scans, 63% negative and 37% positive with a 5-year time to progression of 90% versus 71% and a 5-year overall survival of 97% versus 88%.  Patients with a Deauville-scored PET scan, n=103 patients, the 5-year time to progression for PET negative cases per Deauville criteria, D1-D3, was 91% with inferior outcomes for patients with a D4 or D5 disease, 5-year time to progression 33% versus 87%, P = 0.0002. 

The authors concluded ” outcomes for primary mediastinal B-cell lymphoma treated with R-CHOP are favorable and use of a PET adapted approach reduces radiotherapy in the majority of patients.  A small proportion have refractory disease and may benefit from an alternative treatment.”

https://ashpublications.org/Blood/article-abstract/136/24/2803/461229/Outcome-of-primary-mediastinal-large-B-cell?redirectedFrom=fulltext

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