Do you give post-operative radiation to Ewing sarcoma if there is poor histologic response to neoadjuvant therapy in a completely resected tumor?

US Ewing studies conducted through COG have used histologic response in more recent protocols to play a key role in how margins are assessed, such that patients with >90% necrosis and inflammatory or coagulative necrosis at the margin require RT, while those with bland scar or fibrous tissue do not....