In randomized controlled trials, the addition of RT to chemotherapy increases the progression-free survival but not overall survival in early stage HL. Extended field (EF) and involved field (IF) RT are both associated with late morbidity and mortality, particularly due to second malignancies and cardiovascular events. There do not appear to be safe doses of RT that will remain therapeutic, Doses as low as 20 Gy in CMT do not seem to reduce the risk of second cancers below that seen with traditionally therapeutic doses of 35-45 Gy. The risk of coronary heart disease is increased by 7.4% per Gy in median heart dose. Likewise the reduction of radiation therapy portals from EF to IF RT has not reduced the risk of second cancers. The latest iteration of IF RT is involved site RT (IS RT). However, despite the early observation that initially bulky nodal sites are at higher risk for recurrence than non-bulky sites following adequate chemotherapy, all initial nodal sites are still treated regardless of whether or not they resolve with chemotherapy despite their initial size. Involved site RT still results in large fields encompassing the pre-chemotherapy extent of disease, and as a result, in substantial off-target radiation exposure to adjacent organs. There is no data indicating that lowering the RT dose further in CMT will remain therapeutic. Given the paradigm of treating all initial nodal sites of involvement, it will also be difficult to further substantially reduce off-target radiation exposure, even with new techniques such as three-dimensional conformal RT, intensity modulated RT, deep inspiratory breath hold, or even proton beam RT. Because of these considerations, we propose a change in the paradigm of treating all initial nodal sites of involvement when administering adjuvant RT following adequate chemotherapy. It is unclear whether initial nodal sites that have completely resolved with chemotherapy are at increased risk for recurrence. Rather, we propose clinical trials to test the concept of only treating the PET-negative residual remaining masses on CT imaging following chemotherapy (residual site RT – RS RT). A step in this direction was taken with the HD15 trial.