Radiotherapy Plus Chemo Benefits Certain Patients With DLBCL

Consolidative radiotherapy (RT) can improve outcomes in patients with diffuse large B-cell lymphoma (DLBCL), according to a new systematic review. However, the treatment does not improve overall survival (OS) in all patient groups, the analysis found.

The study, which was published in the Journal of Cellular and Molecular Medicine, found that patients who achieved complete remission (CR) did not benefit from radiotherapy. Patients with bulky disease had longer progression-free survival (PFS), but no significant benefit in terms of OS.

The review also shows that more work is needed, especially related to radiation’s impacts by IPI score and in patients with bulky disease. | Image credit: laszlo – stock.adobe.com

Corresponding author Yao Liu, MD, of China’s Chongqing University Cancer Hospital, and colleagues, said the approval of rituximab (Rituxan) has significantly improved outcomes in patients with DLBCL, noting that the R-CHOP regimen of rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone cures about two-thirds of patients. Yet, they said attempts to further improve outcomes have so far been largely unsuccessful.

“The considerable heterogeneity, along with variations at clinical presentation, prognosis, and therapeutic response, highlights the need for more targeted and personalized treatments,” they wrote.

RT can be an effective treatment in patients with aggressive lymphomas, they noted, but they said a number of important questions remain about the suitability of its use outside of a clinical trial setting. In particular, they said its application in elderly patients, those with varying International Prognostic Index (IPI) scores, and patients in CR remains unclear.

The investigators decided to conduct a systematic review comparing patients with DLBCL who received chemotherapy alone to patients who received chemotherapy with RT.

They found 5 trials, including a total of 1,364 patients who met inclusion criteria.

Liu and colleagues’ analysis showed that patients who underwent consolidative RT had improved OS (HR, 0.46; 95% CI, 0.31-0.68), as well as superior progression-free survival (PFS; HR, 0.52; 95% CI, 0.22-1.25) and event-free survival (EFS; HR, 0.42; 95% CI, 0.20-0.90), compared with patients who did not receive RT. Despite the benefits in the overall cohort, patients with CR did not see improved outcomes from RT.

When the authors analyzed patients based on prognosis, they again found that consolidation RT had a protective effect on patients with advanced IPI scores and advanced stages.

Among patients with bulky disease, consolidation RT improved PFS (HR, 0.50; 95% CI, 0.26-0.94), but had no significant effect on OS, the authors said. Among patients with old age, PFS similarly improved with RT (HR, 0.67; 95% CI, 0.49-0.92), but OS did not.

“In summary, we find that consolidation RT has a significant benefit on OS and EFS for people with DLBCL compared with chemotherapy following a full course of treatment,” they wrote.

The investigators said their review also shows that more work is needed, in particular related to radiation’s impacts by IPI score and in patients with bulky disease. They said the optimal radiation dose for varying patients should also be further studied.

“It has been shown that a dose greater than 40 Gy provides better local control compared to doses below 40 Gy,” they noted. “[H]owever, this finding is somewhat intuitive, and the long-term effects must also be considered.”

They noted that the patients in their meta-analysis received RT doses ranging from 30 to 40 Gy. One study found that radiation dose was not a significant factor for OS after a full course of chemotherapy in patients with early-stage disease.2 Yet, they said other research has suggested that patients with advanced disease benefit from higher doses, they noted.

The authors concluded that their findings were limited by the availability of data. Only data from patients who underwent full courses of chemotherapy was included, and they did not have sufficient data to compare RT plus chemotherapy to chemotherapy alone in patients with low IPIs, young patients, and patients with early-stage disease. They said more work is needed to refine RT therapy within these groups.

References

1. Liang X, Deng X, Xie K, Wang C, Liu Y. The role of radiotherapy after full course of chemotherapy in the treatment of diffuse large B-cell lymphoma: a systematic review and meta-analysis. J Cell Mol Med. 2025;29(18):e70822. doi:10.1111/jcmm.70822

2. Chung MJ, Cho WK, Oh D, et al. A multi-institutional and case-matched control study on treatment outcomes of consolidative radiotherapy after a full course of R-CHOP compared with R-CHOP alone in Stage I-II diffuse large B-cell lymphoma (KROG 17-02). J Radiat Res. 2019;60(5):677-684. doi:10.1093/jrr/rrz043