RATIONALE: A PET scan may help doctors learn how the cancer responded to combination chemotherapy and whether radiation therapy is also required.

PURPOSE: This randomized phase III trial is studying giving a PET scan to see how well it works in deciding whether patients who have received combination chemotherapy for stage IA or stage IIA Hodgkin lymphoma also need radiation therapy.

OBJECTIVES:

• Determine whether patients with stage IA or IIA Hodgkin lymphoma who have a negative fludeoxyglucose F 18 positron emission tomography (FDG-PET) imaging after 3 courses of chemotherapy comprising doxorubicin hydrochloride, bleomycin sulfate, vinblastine, and dacarbazine (ABVD) require consolidation radiotherapy (to areas of previous involvement) in order to delay or prevent disease progression.

OUTLINE: Patients receive doxorubicin hydrochloride IV, bleomycin sulfate IV, vinblastine IV, and dacarbazine IV (ABVD) on days 1 and 15. Treatment repeats every 28 days for 3 courses. On day 15 of the third course of chemotherapy, patients undergo a CT scan of the neck, thorax, abdomen and pelvis. Patients with nonresponsive disease or progressive disease are removed from the study. Patients who achieve response undergo fludeoxyglucose F 18 positron emission tomography (FDG-PET). Patients with a positive FDG-PET scan receive an additional course of ABVD and undergo involved field radiotherapy. Patients with a negative FDG-PET scan are randomized to 1 of 2 treatment arms.

• Arm I: Within 6 weeks after completion of course 3 of chemotherapy, patients undergo involved field radiotherapy to disease areas.
• Arm II: Patients receive no further treatment. After completion of study therapy, patients are followed up every 3 months for 1 year, every 4 months for 1 year, every 6 months for 1 year, and then annually thereafter.

DISEASE CHARACTERISTICS:

• Histologically confirmed Hodgkin Lymphoma

  • Stage IA or IIA disease

    • No stage IA Hodgkin lymphoma with no clinical or CT evidence of disease after diagnostic biopsy

  • Above the diaphragm with no mediastinal bulk, defined as maximum transverse diameter of mediastinal mass

    • Internal thoracic diameter at level of D5/6 interspace > 0.33

  • Bulky disease at other sites, defined as nodal mass with transverse diameter ≥ 10 cm allowed

PATIENT CHARACTERISTICS:

• Not pregnant or nursing
• Fertile patients must use effective contraception during and for ≥ 6 months
• No prior malignancy except appropriately treated basal cell carcinoma of the skin or carcinoma in situ of the cervix
• No severe underlying illness considered to make the trial therapy hazardous (i.e., severe heart disease or lung fibrosis)
• Willing to travel to the nearest PET scan center
• Able to comply with protocol follow-up arrangements

PRIOR CONCURRENT THERAPY:

• No prior treatment for Hodgkin lymphoma
• No contraindications to chemotherapy or radiotherapy