If a patient has multiple PET-avid level 3, supraclavicular, or IMN nodes that are small and would have been considered negative by size criteria with traditional imaging, that are no longer positive on PET after chemotherapy, would you try to boost these nodes?  

I'd certainly cover the initially involved nodal regions, treating typically to 50 Gy and then, if they were small initially and became PET negative after chemo, stop there. The only time I'd consider boosting if there was preserved glucose avidity following chemo. Obviously respect for normal tissu...