Healthcare Professionals   /   OncoLink Scientific Meetings Coverage   /   ASTRO   /   OncoLink at ASTRO 2000   /   OncoLink at ASTRO 2000: Tuesday, October 24

Results From the IRS IV Randomized Trial of Hyperfractionated Radiation in Children with Rhabdomyosarcoma

Joel W. Goldwein, MD
OncoLink co-Editor-In-Chief
Last Modified: October 24, 2000

Presenter: S. S. Donaldson, MD
Affiliation: The Intergroup Rhabdomyosarcoma Study

Background:

• Hyperfractionated radiation therapy (HFRT) has the theoretical potential for improving efficacy without producing more late effects of children with rhabdomyosarcoma (RMS).

• This analysis of the IRS experience in treating rhabdomyosarcomas with HFRT is the first phase III randomized trial of this therapy reported for children

Materials and Methods:

• Children with Group III (gross residual tumor) rhabdomyosarcoma were randomized to receive either 50.4 Gy standard RT or 59.4 Gy in 1.1 Gy BID fractions HFRT, both beginning about week 9 post-resection and after initial chemotherapy

• The dose of HFRT was predicted (based on alpha/beta model) to increase effective tumor dose by 10% without increasing the late toxicity

Results:

• 450 children were analyzed, 251 of whom received HFRT and 239 of whom received conventional RT

• Compliance to radiation protocol was only 57% for patients <= 5 years of age, and 88% for older patients

• Five year actuarial survival was 75%, and relapse-free survival was 70%

• There was no significant difference in survival for the 2 groups

• When analyzed by intent to treat, there was no significant difference on freedom-from-relapse for the 2 groups

• Local failure rate was 12% for the conventional RT patients and 15% for the HFRT patients; this was not significantly different

• Grade III and IV toxicity was 86% in the conventional RT group and 89% in the HFRT group; also not significantly different

Authors' Conclusions

• HFRT as described above does not improve tumor control in these patients

Clinical/Scientific Implications:

• Conventional RT remains the standard of care for children with Group III rhabdomyosarcoma