Radiation Therapy in Lymphoma

Presentation Description / Summary: Lymphoma is considered a systemic disease process and thus treated with chemotherapy. Many different protocols have been exhaustively evaluated over the last 40 to 50 years and several new drugs have been developed. Despite initially good response rates and remission durations with chemotherapy most patients eventually relapse and ultimately succumb to disease. Radiation therapy for the treatment of lymphoma in veterinary medicine has largely focused on treatment of localized disease, such as feline nasal lymphoma. Low dose half body irradiation has been evaluated in dogs receiving CHOP based chemotherapy protocols and suggests an improvement in long term outcome may occur. Abdominal radiation therapy has also been evaluated in cats with gastrointestinal lymphoma with mixed results. In both situations radiation was used to consolidate chemotherapy once the individual patient was already in remission. In human medicine strategies involving radiation therapy for the treatment of extra nodal lymphoma are well reported for primary treatment, consolidation after chemotherapy, salvage or rescue, and palliative purposes. Radiation for the treatment of nodal lymphoma is also utilized in humans, known as Involved Node Radiation Therapy (INRT). We plan to discuss a variety of cases where radiation therapy was utilized to achieve rapid improvement of clinical signs, stabilization of patients prior to initiating chemotherapy, treatment of patients currently receiving chemotherapy that may have residual localized disease and cases that are resistant to chemotherapy.

Learner Outcomes: 1. Become familiar with the utilization of radiation therapy in the treatment of lymphoma in humans. 2. Understand the current veterinary literature and theory behind radiation strategies utilized in veterinary patients with lymphoma. 3. Identification of patients with lymphoma that may benefit from the addition of radiation therapy into their treatment protocol.