An international, multicentre, randomised cntrolled trial for paediatric classical Hodgkin Lymphoma. The overall strategy is risk stratified (defining chemotherapy) and response adapted (defining radiotherapy) to tailor the amount of treatment to the individual patient and decrease long term complications. Patients are stratified by early PET response; those with an adequate response may avoid radiotherapy to reduce long term sequelae. It evaluates the efficacy of intensified chemotherapy (COPDAC vs DECOPP) in intermediate and high risk groups to optimise the balance between cure and toxicity. Primary endpoints include event free survival and the reduction of treatment related late effects through the selective omission of radiation therapy.