Low-dose radiotherapy (2×2 g) versus low doses and rituximab in the treatment of marginal zone b-cell lymphoma previously untreated.

Unlabelled: Radiotherapy (RT)is considered the treatment of choice in patients with Extra-nodal marginal zone lymphoma (EMZL) at early stage, but the presence of late toxicities has been limited the acceptance. Recently, low doses of RT LDR) (2 x 2 Gy) and the use of limited fields has been observed that retain the efficacy but eliminate toxicities; rituximab is considered as a single agent useful in these setting of patients. Thus, we conducted a open label study to evaluate the use of LDR compared with LDR and rituximab, in a large number of patients without previous treatment.

Methods: Patients with pathological diagnosis or(EMZL)), stage I, without previous treatment, were allocated in a proportion 1:1 to received LDR) that were compared with a group that received LDR and rituximab.

Results: One hundred and fourteen patients were recruit ; overall response rate and complete response were : 58(98.3%) and 54 (96.4 %)in patients whose respectively in LDR that were no statistical different to the observed in the LDR + R arm: 53 (96.3%) and 51 (92.75 %) respectively. Actuarial curves at 5-years show that progression-free survival in LDR arm were: 98.4% (95% Confidence interval (CI): 93%-108%) and OS were 97.2% (95%CI: 92%-110%), that did no show statistical difference with the LDR-R arm: 96.4% (95%CI: 90%-110%), and 98.5%(95%CI:92%-107%) respectively. Univariate analysis did not show any statistical differences in the analysis of prognostic factors. Acute and late toxicities were not observed.

Conclusion: We conclude that LDR will be considered as the treatment of choice in patients with EMZL, in early stage, localized in head and neck anatomical sites; because response and outcome were excellent, without any toxicity, addition of rituximab did not improve results and outcome.