减量（24 Gy）受累部位放疗联合利妥昔单抗治疗早期非胃黏膜相关淋巴组织淋巴瘤：一项前瞻性 II 期试验

While involved-site radiotherapy (ISRT) is the standard first-line treatment in localized non-gastric mucosa-associated lymphoid tissue (MALT) lymphoma, the cumulative risk of distant relapse poses a persistent clinical challenge.

We conducted a prospective phase II trial evaluating rituximab with 24 Gy ISRT, aiming to reduce distant relapse and enhance long-term survival. By October 2025, 60 patients with early-stage non-gastric MALT lymphoma were enrolled. Among the per-protocol efficacy-evaluable cohort (n = 55), the combined immunoradiotherapy regimen achieved a complete response rate of 100%. At a median follow-up of 30. 2 months, only one distant recurrence was observed (estimated 5-year distant recurrence: 1. 9%). In the full analysis set, 2- and 4-year progression-free survival rates were 98.

0% and 92. 9%, respectively, improving to 100% and 94. 4% in the per-protocol set. Treatment-related hematologic toxicity was frequent but manageable. Infections were reported in 23. 3%, including one grade 4 respiratory infection that necessitated treatment discontinuation. Immunophenotypic profiling revealed that parotid, thyroid, or mediastinal involvement correlated with higher lymphocyte proportions (39. 5% 16. 4%, P = 0. 012). Post-treatment immunologic changes featured near-complete B-cell depletion and a compensatory expansion of NK cells.

Overall, the combined immunoradiotherapy regimen demonstrated durable disease control in localized non-gastric MALT lymphoma, with potential synergistic benefit from NK cell-mediated immune activation. Trial registration: Chinese Clinical Trials Registry, ChiCTR2000036318; registered on Aug 22, 2020 (prospective).