Cycle Number (chemotherapy re-challenge)   1 2 3 4 5 Rituximab (mg IV) 560 560 560 560 560 Doxorubicin (mg IV) 30 30 45 45 45 Vincristine (mg IV) 1 1 0.5 0.5 0.5 Cyclophosphamide (mg IV) - 750 900 900 900 Prednisone (mg PO) 100 for 5days 100 for 5days 100 for 5days 100 for 5days 100 for 5days

Table 1: Chemotherapeutic regimen used during rechallenges. The slow escalation in doses is empiric since data from the literature is limited. This allowed close monitoring of cardiac function and early recognition of potential cardiac toxicity.