What is the Role of Radiation Therapy for Patients with Primary or Relapsed Hodgkin Lymphoma

Classical Hodgkin lymphoma (HL) challenges clinicians to devise treatment strategies that are effective and safe. This problem is particularly prominent in an era when de-escalation trials are designed to minimize therapeutic toxicities in both early and advanced stage disease. Radiation therapy is the single most effective (stand-alone) treatment modality for HL, and its integration into upfront and salvage regimens must be understood in order to maximize our success in treating these patients. The complexity of HL derives from the spectrum of primary treatment approaches currently in use that creates heterogeneity in both treatment exposure and the potential toxicities. Response-based treatment paradigms have improved our ability to titrate therapy in this era of precision medicine. New biologics and immunotherapeutic approaches have broadened but also complicated both primary and salvage treatment strategies. Patients can have relapsed or refractory disease after limited or aggressive primary therapy (with or without radiation therapy) with varying degrees of residual morbidity from primary therapy. Their response to salvage systemic therapy can be partial or complete, and the use of consolidative stem cell transplant is variably applied. Through all of this, radiation therapy remains an integral component of treatment for many patients but it must be used effectively and judiciously. The purpose of this discussion is to provide guidance for the use of radiation therapy in patients with primary, relapsed or refractory HL.