Blood Res.  2025;60:27. 10.1007/s44313-025-00076-4.

Real‑world data analysis of survival outcomes of patients with primary mediastinal large B‑cell lymphoma treated with immunochemotherapy: the role of consolidative radiation therapy

• Lee Y
• Cho J
• Ko Y
• Oh D
• Kim S
• Kim W
• Yoon S

• KMID: 2567368
• DOI: http://doi.org/10.1007/s44313-025-00076-4

Abstract

Purpose
Primary mediastinal large B-cell lymphoma (PMBCL) is a rare subtype of diffuse large B-cell lymphoma. Radiation therapy (RT) has served as the primary treatment option for PMBCL; however, its role has been questioned with the advent of intensified immunochemotherapy. This study aimed to investigate the role of consolidative RT in the primary treatment of PMBCL.
Methods
This single-center retrospective study analyzed the survival outcomes of 65 patients newly diagnosed with PMBCL. The patients were divided into three treatment groups: (1) EPOCH-R (etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin, and rituximab), (2) R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone), and (3) R-CHOP with consolidative RT.
Results
The objective response and complete remission rates were 86.2% and 63.1%, respectively, with 3-year pro‑ gression-free survival (PFS) and overall survival (OS) rates of 72% and 81%, respectively. All patients in the R-CHOP + RT group achieved an objective response with better PFS) than those who did not receive consolidative RT (p = 0.028), although there was no significant difference in OS (p = 0.102). Consolidative RT benefited patients with an initially bulky disease or insufficient end-of-treatment response. The predictive value of  18 F-fluorodeoxyglucose positronemission tomography-computed tomography (PET-CT) in assessing the treatment response in PMBCL was revali‑ dated, showing that patients who achieved negative end-of-treatment PET-CT had significantly better survival outcomes than others.
Conclusions
R-CHOP is a useful alternative regimen when intensified chemotherapy is not feasible. Consolidative RT should be considered in cases with an initially bulky disease and insufficient end-of-treatment response.

Keyword

Primary mediastinal large B-cell lymphoma; Front-line immunochemotherapy; Radiation therapy; Consolidative treatment

Figure

• 

  Fig. 1 Flow diagram of the study population

• 

  Fig. 2 Overall achievement of an objective response and/or complete response (A). Comparison of responses to the three primary treatment regimens (B). Kaplan–Meier curves of progression-free survival (PFS) (C) and overall survival (OS) (D) according to primary treatment. Comparison of PFS (E) and OS (F) according to the three primary treatment regimens. Comparison of PFS (G) and OS (H) according to radiation therapy in patients with bulky disease at diagnosis

• 

  Fig. 3 End-of-treatment (EOT) PET-CT) results according to radiation therapy (RT) in patients treated with R-CHOP (A). Sankey diagram of patients treated with R-CHOP showing interim and EOT PET-CT responses (B). Comparison of interim and EOT PET-CT responses according to RT in patients treated with R-CHOP (C). Comparison of progression-free survival (PFS) (D) and overall survival (OS) (E) according to interim PET-CT findings. Comparison of PFS (F) and OS (G) according to EOT PET-CT findings. Comparison of PFS (H) and OS (I) according to the interim and EOT PET-CT findings. Comparison of PFS (J) and OS (K) according to RT administration in patients with DS 3 and 4. PET-CT; positron emission tomography-computed tomography, R-CHOP; rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone, DS; Deauville scale

• 

  Fig. 4 Comparison of disease relapse among the three primary treatment modality groups (A). Swimmer plot of relapsed patients (B). Comparison of overall survival (OS) according to patterns of disease relapse (C). Sankey diagram showing the PET-CT response and disease relapse (D). Kaplan–Meier curves of OS of patients with disease relapse (E). PET-CT; positron emission tomography-computed tomography

• 

  Fig. 5 Swimmer plot of relapsed patients treated with immune checkpoint inhibitors

Reference

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