The analysis set consisted of @ patients with residues@ @ cm after chemotherapy from a total of @,@ patients treated in the HD@ trial ( HD@ for advanced stage Hodgkin 's disease : Quality assurance protocol for reduction of toxicity and the prognostic relevance of fluorodeoxyglucose-positron-emission tomography -LSB- FDG-PET -RSB- in the first-line treatment of advanced-stage Hodgkin 's disease ) performed by the German Hodgkin Study Group .