Early-Stage Diffuse Large B-Cell Lymphoma

Diffuse large B-cell lymphoma (DLBCL) is the most common high-grade non-Hodgkin lymphoma. Standard first-line treatment includes immuno-chemotherapy, most commonly consisting of 3–6 cycles of R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone). In some cases, consolidation radiation therapy (RT) is recommended after systemic therapy. In the modern era of combined-modality treatment, historical extended radiation fields have been replaced with smaller, individualized volumes that target initial sites of involvement, referred to as involved-site radiation therapy (ISRT). A positron emission tomography (PET)/computed tomography (CT) scan performed after immuno-chemotherapy and before ISRT informs the appropriate radiation dose, with 30 Gy recommended in the setting of a complete metabolic response and higher doses recommended if there is residual metabolically active disease. The appropriate patient immobilization, radiation technique, and image guidance vary based upon the anatomical site of involvement. In this chapter, we summarize the use of ISRT in early-stage DLBCL and present cases that highlight modern target delineation and treatment planning.