Randomized comparison of low-dose involved-field radiotherapy and no radiotherapy for children with Hodgkin's disease who achieve a complete response to chemotherapy.

Purpose

Current standard therapy for children and adolescents with Hodgkin's disease includes combination chemotherapy and low-dose involved-field radiation (LD-IFRT). Because radiation may be associated with adverse late effects, the Children's Cancer Group (CCG) investigated whether radiation could be omitted in patients achieving a complete response to initial chemotherapy without jeopardizing the excellent outcome obtained with combined-modality therapy.

Patients and methods

Between January 1995 and December 1998, 829 eligible patients were enrolled onto CCG 5942. A total of 501 patients who achieved an initial complete response after risk-adapted combination chemotherapy were randomized to receive LD-IFRT or no further treatment. Event-free survival (EFS) and overall survival were assessed from the date of study entry or the date of randomization, as appropriate.

Results

The projected 3-year EFS from study entry for the entire cohort was 87% +/- 1.2%. Among patients who achieved a complete response to initial chemotherapy, 92% +/- 1.9% of those randomized to receive LD-IFRT were alive and disease free 3 years after randomization, versus 87% +/- 2.2% for patients randomized to receive no further therapy (stratified log-rank test; P =.057). With an "as-treated" analysis, 3-year EFS after randomization for the radiation cohort was 93% +/- 1.7% versus 85% +/- 2.3% for patients receiving no further therapy (stratified log-rank test; P =.0024). Three-year survival estimates for patients treated with and without LD-IFRT were 98% +/- 1.1% for patients who received radiation and 99% +/- 0.5% for patients who did not receive radiation.

Conclusion

LD-IFRT after an initial complete response to risk-adapted chemotherapy improved EFS. At this time, there is no survival advantage for LD-IFRT, but follow-up remains short.