Pretherapy and posttherapy fused PET/CT images in a 17-year-old female patient with nodular sclerosis Hodgkin disease. The pretherapy images (top) showed bilateral supraclavicular, anterior mediastinal, and left hilar lymphadenopathy by both PET and CT. Posttherapy PET/CT performed 4 weeks following completion of 6 cycles of ABVD (doxorubicin, bleomycin, vinblastine, dacarbazine) showed resolution of disease in the supraclavicular and left hilar region but continued to show a residual 6.2 × 3.4-cm mass in the anterior mediastinum that was PET negative. Multiple biopsies of the mass showed only fibrous tissue with no evidence of lymphoma. The patient is currently without evidence of disease after 4 years of follow-up.