Long-term follow-up of patients with early-stage diffuse large B-cell lymphoma of Waldeyer’s ring treated with intensity-modulated radiotherapy

Abstract

Objective To evaluate the treatment outcome, prognostic factors, radiation dose, and toxicities in patients with early-stage primary diffuse large B-cell lymphoma of Waldeyer’s ring (WR-DLBCL) treated with intensity-modulated radiotherapy (IMRT). Methods This study included 80 patients with a confirmed diagnosis of stage Ⅰ—Ⅱ primary WR-DLBCL who were admitted to our hospital from 2008 to 2015. Only 3 patients received radiotherapy alone, and the other patients received radiotherapy and chemotherapy. After chemotherapy, 24 patients achieved complete remission (CR), and 53 patients achieved partial remission (PR). IMRT was given to the primary lesion and cervical lymphatic drainage region. Survival analysis was performed using the Kaplan-Meier method and log-rank test. The Cox model was used for analysis of prognostic factors. The toxicities were scored using the RTOG criteria. Results The median follow-up was 64 months. The 5-year locoregional control (LRC), overall survival (OS), and progression-free survival (PFS) rates were 94%, 88%, and 84%, respectively. The dose-volume histogram showed that the maximum, mean, and minimum doses to primary gross tumor volume were 54.47 Gy, 52.27 Gy, and 38.83 Gy, respectively. Prognostic analysis showed that age>60 years and increased lactate dehydrogenase (LDH) were influencing factors for OS (P=0.009 and 0.002), and that aged>60 years, IPI ≥2, and increased LDH were influencing factors for PFS (P=0.001, 0.035, and 0.007). Among all patients, 12, 53, and 8 experienced grade 1-3 radiation-induced acute oral mucositis, respectively, and 16 and 13 experienced grade 1 and 2 xerostomia as the late toxicity, respectively. Conclusions For patients with early-stage primary WR-DLBCL, IMRT results in satisfactory OS, PFS, and LRC and has tolerable early or late radiation-induced toxicities. Key words: Lymphoma/intensity modulated radiotherapy; Lymphoma, Waldeyer’s ring; Lymphoma, diffuse large B-cell; Treatment outcome