RATIONALE: Drugs used in chemotherapy, such as vincristine, dactinomycin, cyclophosphamide, and irinotecan, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Radiation therapy uses high-energy x-rays to kill tumor cells. Giving combination chemotherapy together with radiation therapy may kill more tumor cells. It is not yet known which combination chemotherapy regimen is more effective when given together with radiation therapy in treating patients with rhabdomyosarcoma.

PURPOSE: This randomized phase III trial is studying two different combination chemotherapy regimens to compare how well they work when given together with radiation therapy in treating patients with newly diagnosed rhabdomyosarcoma.