Using Deauville Scoring to Guide Consolidative Radiotherapy in Diffuse Large B-Cell Lymphoma

Area of Science:

• Oncology
• Radiotherapy
• Nuclear Medicine

Background:

• Diffuse large B-cell lymphoma (DLBCL) is an aggressive adult lymphoma.
• Consolidative radiotherapy (RT) is common but its guidelines are unclear, risking unnecessary treatment.
• Evaluating end-of-treatment PET-CT scans with Deauville score (DV) can guide RT decisions and spare low-risk patients.

Purpose of the Study:

• To assess the value of end-of-treatment PET-CT scans (DV) in guiding consolidative RT for DLBCL.
• To determine if DV can identify DLBCL patients who may not benefit from RT.
• To potentially reduce unnecessary RT in low-risk DLBCL patients.

Main Methods:

• Retrospective analysis of 349 DLBCL patients diagnosed between 2010-2022.
• Inclusion of patients with end-of-treatment PET-CT DV measurements after first-line chemoimmunotherapy.
• Time-to-progression (TTP) as the primary outcome, analyzed using Cox regression to assess RT's predictive value based on DV.

Main Results:

• RT significantly improved TTP in DV4-5 patients (HR 0.33, p=0.027) but not in DV1-3 patients (HR 0.85, p=0.671).
• Multivariable analysis confirmed RT's benefit for DV4-5 patients (aHR 0.29, p=0.017) but not DV1-3 patients (aHR 0.86, p=0.707).
• Interaction p-values were 0.133 (univariable) and 0.087 (multivariable), suggesting a trend but not statistical significance in differential treatment effect.

Conclusions:

• DLBCL patients with end-of-treatment PET-CT DV1-3 may not require consolidative RT.
• Further long-term follow-up and prospective randomized trials are needed.
• DV scoring on PET-CT shows potential for personalizing RT decisions in DLBCL.