Abstract
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Objectives We aimed to evaluate the prognostic value of interim positron emission tomography/computed tomography (PET/CT) interpreted using qualitative visual trichotomous assessment (QVTA) criteria in patients with diffuse large B-cell lymphoma (DLBCL) treated with rituxim
Methods We enrolled 306 patients in this study. All PET/CT images obtained after two chemotherapy cycles (PET/CT2) were reviewed according to QVTA criteria and labeled positive or negative if all three interpreters agreed. All other results were considered indeterminate.
Results Results: After four cycles of R-CHOP, the overall response rate (ORR) for patients with positive, indeterminate, and negative PET/CT2 was 54.5%, 95.7%, and 100%, respectively (p < 0.05). After six cycles of R-CHOP, the ORR for patients with positive, indeterminate, and negative PET/CT2 was 27.3%, 87.1%, and 97.8%, respectively (p < 0.05). The rate of 2-year overall survival (OS) for patients with positive, indeterminate, and negative PET/CT2 was 45.1%, 83.4%, and 94.5%, respectively (p < 0.001).
Conclusions Conclusion: Interim PET/CT interpreted using QVTA criteria is feasible for therapeutic evaluation during treatment. A negative PET/CT finding identifies a group with an ORR of 97.8%, and a unanimously positive PET/CT result differentiates chemoresistant lymphoma from complete response and can be used to guide risk-adapted therapy. Most patients with indeterminate PET/CT results could continue to benefit from R-CHOP treatment.