Association between radiotherapy vs no radiotherapy based on early response to VAMP chemotherapy and survival among children with favorable-risk Hodgkin lymphoma

Context: More than90%of children with favorable-risk Hodgkin lymphoma can achieve long-term survival, yet many will experience toxic effects from radiation therapy. Pediatric oncologists strive for maintaining excellent cure rates while minimizing toxic effects. Objective: To evaluate the efficacy of 4 cycles of vinblastine, Adriamycin (doxorubicin), methotrexate, and prednisone(VAMP)in patients with favorable-risk Hodgkinlymphoma who achieve a complete response after 2 cycles and do not receive radiotherapy. Design, Setting, and Patients: Multi-institutional, unblinded, nonrandomized single group phase 2 clinical trial to assess the need for radiotherapy based on early response to chemotherapy. Eighty-eight eligible patients with Hodgkin lymphoma stage I and II (<3 nodal sites, no B symptoms, mediastinal bulk, or extranodal extension) enrolled between March 3, 2000, and December 9, 2008. Follow-up data are current to March 12, 2012. Interventions: The 47 patients who achieved a complete response after 2 cycles received no radiotherapy, and the 41 with less than a complete response were given 25.5 Gy-involved-field radiotherapy. Main Outcome Measures: Two-year event-free survival was the primary outcome measure. A 2-year event-free survival of greater than 90% was desired, and 80% was considered to be unacceptably low. Results: Two-year event-free survival was 90.8% (95% CI, 84.7% - 96.9%). For patients who did not require radiotherapy, it was 89.4% (95% CI, 80.8%-98.0%) compared with 92.5% (95% CI, 84.5%-100%) for those who did (P=.61). Most common acute adverse effects were neuropathic pain (2% of patients), nausea or vomiting (3% of patients), neutropenia (32% of cycles), and febrile neutropenia (2% of patients). Nine patients (10%) were hospitalized 11 times (3% of cycles) for febrile neutropenia or nonneutropenic infection. Long-term adverse effects after radiotherapy were asymptomatic compensated hypothyroidism in 9 patients (10%), osteonecrosis and moderate osteopenia in 2 patients each (2%), subclinical pulmonary dysfunction in 12 patients (14%), and asymptomatic left ventricular dysfunction in 4 patients (5%). No second malignant neoplasms were observed. Conclusions: Among patients with favorable-risk Hodgkin lymphoma and a complete early response to chemotherapy, the use of limited radiotherapy resulted in a high rate of 2-year event-free survival. Trial Registration: Clinicaltrials.gov Identifier: NCT00145600.