One of the most difficult challenges in the management of lymphoma is the proper definition of the appropriate volume for contouring. With the evolution from the mantle field to the involved field and even involved nodal field, it can be very challenging for the non lymphoma site specific expert to feel comfortable delineating the appropriate volumes. This can be complicated by the interpretation of the pre and post treatment imaging studies. This course incorporates both a radiologist and a radiation oncologist to optimize the imaging evaluation of lymphoma patients as it relates to specific contouring guidelines. After this course, participants will be able to demonstrate competence in correctly contouring the appropriate volumes for treatment. At the conclusion of this activity, the learner will be able to do the following: 1. Explain a basic understanding of nodal anatomy and implications for radiotherapeutic field design and conformal therapy for disease sites in the neck, chest, abdomen, and pelvis with a special emphasis on the supradiaphragmatic regions. 2. Identify target nodal volumes and critical structures with a particular emphasis on the evolution of treatment field design incorporating both involved field and involved node radiation therapy. 3. Discuss the role of imaging modality selection to aid in treatment design. 4. Discuss the implications of radiotherapy technique on target volume and margin size.