Role of radiotherapy in patients with limited diffuse large B-cell lymphoma of Waldeyer's ring in remission after R-CHOP immunochemotherapy.

The standard treatment of waldeyer's ring DLBCL remains controversial. This retrospective study was designed to evaluate the role of consolidation radiotherapy (RT) in patients with stage I/II diffuse large B-cell lymphoma (DLBCL) limited in Waldeyer's ring (WR). We included 72 patients, 42 were treated with immunochemotherapy alone (CT group) and 30 were treated with immunochemotherapy followed by radiotherapy (CT + RT group). All patients received at least 3 cycles of R-CHOP regimen and achieved complete remission (CR) after immunochemotherapy. After 53 months median follow-up time, the 5-year progression-free survival (PFS) rates in CT + RT group vs. CT group were 93.3% vs. 92.5% (P = 0.896), the 5-year overall survival (OS) rates were 96.7% vs. 94.4% (P = 0.649). Patients with oropharyngeal primary had relatively better 5-year PFS and OS rates compared to nasopharyngeal primary (PFS: 98.2% vs. 73.3%, p = 0.001; OS: 100% vs. 79.0%, p < 0.001). Moreover, the primary site was the only independent prognostic factor for PFS in the multivariate analysis (p = 0.012, HR 16.858 [95% CI: 1.883-150.933]).