- Arm A (ABVD): Patients receive doxorubicin (25 mg/m²), bleomycin (10 u/m²), vinblastine (6 mg/m²), and dacarbazine (375 mg/m²) IV on days 1 and 15. Courses repeat every 28 days. Patients are restaged after 4 courses. Patients who are in complete remission receive 2 additional courses. Patients with a partial response or less are evaluated after 6 courses, and if there is an ongoing response, patients may receive 2 additional courses for a total of 8. If no ongoing response is observed, patients are removed from the study. All patients with massive mediastinal disease, regardless of stage, receive radiotherapy 2-3 weeks after completion of chemotherapy.