S0816 Fludeoxyglucose F 18-PET/CT Imaging and Combination Chemotherapy With or Without Additional Chemotherapy and G-CSF in Treating Patients With Stage III or Stage IV Hodgkin Lymphoma

RATIONALE: Drugs used in chemotherapy work in different ways to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. Giving more than one drug (combination chemotherapy) may kill more cancer cells. G-CSF may help lessen the side effects in patients receiving chemotherapy. Imaging procedures, such as fludeoxyglucose F 18-PET/CT imaging, may help doctors predict how patients will respond to treatment. PURPOSE: This phase II trial is studying fludeoxyglucose F 18-PET/CT imaging to see how well it works in assessing response to combination chemotherapy and allow doctors to plan better additional further treatment in treating patients with stage III or stage IV Hodgkin lymphoma.