Loco‐regional radiotherapy in de novo metastatic nasopharyngeal carcinoma with chemotherapy and immunotherapy: A real‐world retrospective study from two cancer centers

Abstract Background Immunochemotherapy has become the first‐line treatment for initial diagnosed metastatic nasopharyngeal carcinoma (mNPC). Loco‐regional radiotherapy combined with systemic chemotherapy significantly improves the survival. However, the safety and efficacy of loco‐regional radiotherapy combined with immunochemotherapy remained unknown. Methods Patients with de novo mNPC who received immunochemotherapy followed by loco‐regional radiotherapy were included from two cancer centers. Toxicity and treatment response were assessed using CTCAE 5.0 and RECIST 1.1, respectively. Overall survival (OS) and progression‐free survival (PFS) were analyzed using the Kaplan–Meier method. Results From 2019 to 2021, a total of 16 patients were retrospectively analyzed. The median follow‐up was 28 months (range 14–47 months). No one died. One‐year, 2‐year, and 3‐year PFS rate was 93.8%, 58.4% and 50.1%, respectively. Radiotherapy‐related acute severe (grade 3 or higher) toxicity was dermatitis (1/16, 6.3%) and mucositis (2/16, 12.5%). Conclusions Loco‐regional radiotherapy provided a promising efficacy with modest toxicity for patients with mNPC who received immunochemotherapy.