Deauville score evaluation of interim PET/CT in primary mediastinal large B-cell lymphoma

Abstract

Dear Sir, We read with great interest the article by Lazarovici et al. [1], in which the authors retrospectively analyzed the prognostic value of interim positron emission tomography/computed tomography (PET/CT) in primary mediastinal large B-cell lymphoma (PMBCL). The study enrolled 36 consecutive PMBCL patients, and all PET/ CT scans were interpreted using the International Harmonization Project (IHP) criteria and reviewed according to the more recent Deauville criteria. The authors concluded that interim PET/CT exhibited poor positive predictive values in PMBCL regardless of using IHP criteria or Deauville criteria. However, we noticed that according to the Deauville criteria, all 36 patients are of Deauville 1–4, with clinical outcomes of patients with Deauville 5 remaining unclear. Therefore, to investigate the prognostic value of interim Deauville 5 in PMBCL, we conducted a retrospective study on 49 patients with newly diagnosed PMBCL at our institute. From February 2014 to May 2020, 49 newly diagnosed PMBCL patients were included in this study. Histological diagnosis was established according to the World Health Organization 2016 classification [2]. All patients underwent PET/CT scans at baseline, 3 weeks after three cycles of treatment, and 6 weeks after all cycles of treatment. PET/CT scans were performed on a Discovery VCT system (GE Healthcare, USA). Patients underwent fasting for at least 6 h before an intravenous administration of 5–6 MBq of [F]fluorodeoxyglucose per kilogram of body weight. The serum glucose level before injection was kept under 7.0 mmol/L. Patients were imaged from head to thigh. The CT scan data were collected at 120–180 mAs, 140 kV, with a gantry rotation speed of 0.8 s. PET and CT images were integrated on Xeleris (GE Healthcare, Chicago, IL) and Advantage workstat ions (GE Healthcare, Chicago, IL). Two experienced nuclear medicine physicians reviewed PET/CT images. According to the Deauville criteria, the interim assessment was obtained using mediastinum and liver uptake as references [3, 4]. We summarized the main characteristics of the 49 patients in Table 1. Among all 49 patients, 22 (44.9%) received rituximab combined with cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP), and 27 (55.1%) patients received dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin combined with rituximab (DAEPOCH-R). Out of the 49 patients, 14 (28.6%) patients also received consolidation mediastinal radiation. Clinical outcomes of the patients according to the Wei Qin, Xufeng Jiang and Jianhua You contributed equally to this work.