Interim PET/CT Result Is Not Predictive of Survival in Patients With MYC-rearranged Non-Burkitt Aggressive B-cell Lymphoma.

Background: Patients with a diagnosis of MYC-rearranged non-Burkitt aggressive B-cell lymphoma (MYC-R), including those with double hit lymphoma, are at high risk of developing relapsed/refractory disease, even if treated with intensive front-line immunochemotherapy. It is common in clinical practice and clinical trials to perform an interim positron emission tomography (PET)/computed tomography (CT) scan (iPET) during front-line therapy for diffuse large B-cell lymphoma. However, the utility of the iPET result for MYC-R patients for predicting outcomes is unclear.

Patients And Methods: We performed a single-center retrospective study with centralized pathologic review and PET/CT image acquisition and interpretation for 28 MYC-R patients. The patients received front-line therapy with R-CHOP (rituximab, cyclophosphamide, hydroxydaunorubicin [doxorubicin], Oncovin [vincristine], prednisone) or intensive immunochemotherapy.

Results: Eight patients had iPET-positive (iPET) and 20 patients had iPET-negative (iPET) results using the Deauville visual assessment criteria. At a median follow-up length of 30.4 months, progression-free survival was 65% and overall survival was 76%, neither of which differed significantly between the iPET and iPET patients. The positive predictive value of iPET for progression at 30 months was 25%, and the negative predictive value was 65%.

Conclusion: Although patients with MYC-R lymphoma have been reported to be at high risk of primary treatment failure, this was not predicted by iPET results. Thus, the iPET result should not be used to guide changes in front-line or consolidative therapy for these patients.