Fludeoxyglucose F 18 PET Scan-Guided Therapy or Standard Therapy in Treating Patients With Previously Untreated Stage I or Stage II Hodgkin's Lymphoma

DISEASE CHARACTERISTICS: * Histologically confirmed Hodgkin's lymphoma * No nodular lymphocyte-predominant subtype (nodular paragranuloma) * Supradiaphragmatic Ann Arbor clinical stage I or II disease * Must meet criteria for 1 of the following prognostic subsets: * Unfavorable subset, defined as meeting 1 of the following criteria: * Clinical stage II disease with ≥ 4 nodal areas involved * Mediastinum and hili are considered as 1 nodal area * Age ≥ 50 years * Erythrocyte sedimentation rate (ESR) ≥ 50 mm/hr with no B symptoms * ESR ≥ 30 mm/hr with B symptoms * Mediastinum/thoracic (MT) ratio ≥ 0.35 * Favorable subset, defined as meeting all of the following criteria: * Clinical stage I disease OR stage II disease with ≤ 3 involved areas * Age \< 50 years * ESR \< 50 mm/hr (no B symptoms) OR ESR \< 30 mm/hr (B symptoms present) * MT ratio \< 0.35 * Previously untreated disease * Planning to undergo fludeoxyglucose F 18 positron emission tomography after the first 2 courses of study chemotherapy PATIENT CHARACTERISTICS: * WHO performance status 0-3 * Bilirubin ≤ 2.5 times upper limit of normal (ULN) * Creatinine ≤ 2.5 times ULN * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * No severe cardiac, pulmonary, neurologic, psychiatric, or metabolic disease * No unstable diabetes mellitus * No other malignancies within the past 5 years except for basal cell skin cancer or …