Fludeoxyglucose F 18-PET/CT Imaging in Assessing Response to Chemotherapy in Patients With Newly Diagnosed Stage II, Stage III, or Stage IV Hodgkin Lymphoma

DISEASE CHARACTERISTICS: * Histologically confirmed classical Hodgkin lymphoma (HL) meeting the following criteria: * Meets current WHO classification criteria (i.e., nodular sclerosis, mixed cellularity, lymphocyte rich, and lymphocyte-depleted) * Clinical stage IIB, III, or IV disease OR clinical stage IIA disease with adverse features, including any of the following: * Bulk mediastinal disease, defined as maximal transverse diameter of mass \> 0.33 of the internal thoracic diameter at D5/6 interspace on routine chest x-ray * Disease outside the mediastinum and lymph node or lymph node mass \> 10 cm in diameter * More than two sites of disease * Other poor-risk features that require treatment with full course combination chemotherapy * Newly diagnosed disease * No CNS or meningeal involvement by lymphoma PATIENT CHARACTERISTICS: * ECOG performance status 0-3 * Life expectancy \> 3 months * ANC \> 1,500/mm\^3 (unless there is bone marrow infiltration by lymphoma) * Platelet count \> 100,000/mm\^3 (unless there is bone marrow infiltration by lymphoma) * Creatinine \< 150% of upper limit of normal (ULN) * Bilirubin \< 2.0 times ULN (unless attributed to lymphoma) * Transaminases \< 2.5 times ULN (unless attributed to lymphoma) * LVEF ≥ 50% (in patients with a significant history of ischemic heart disease or hypertension) * Diffusion capacity within 25% of normal predicted value by lung function testing * Not pregnant or nursing * Negative pregnancy tes…