The new German evidence-based guideline on diffuse large B-cell lymphoma-key aspects for radiation oncologists.

PURPOSE: Diffuse large B­cell lymphoma (DLBCL) is an aggressive lymphoma subtype treated successfully with immunochemotherapy. However, there are conflicting data on the role and impact of consolidative radiation therapy (RT). The publication of the national evidence-based guideline on DLBCL prompted us to review relevant passages on radiation oncology. METHODS: The following article reviews the evidence and recommendations given in the current German evidence-based guideline on DLBCL regarding RT and summarizes pivotal aspects. Additional literature is presented to provide a comprehensive background for the published recommendations. RESULTS: RT shall be administered to all patients with localized positron emission tomography(PET)-positive residues after completion of immunochemotherapy and should use a dose of 30-40 Gray in normofractionation. For RT planning, PET information before and after immunochemotherapy shall be used, with either a PET-CT in the RT treatment position or an image fusion to the planning CT. Conformal techniques shall be used for target volume coverage, with a risk-benefit evaluation for the individual patient. Additionally, RT may be used in the treatment context of various subtypes of DLBCL as well as in the recurrent or refractory treatment situation. CONCLUSION: RT remains an integral part of the treatment repertoire of DLBCL. With the use of PET-guided treatment, RT is indicated for patients with metabolically active tumors. In the context of the ongoing development of targeted therapies, new RT indications may evolve.