This study is for patients with a type of cancer called intermediate-risk rhabdomyosarcoma (IR RMS). Two types of chemotherapy are being compared: a higher dose over a shorter time and a lower dose with extra maintenance treatment over a longer time. Chemotherapy uses strong medicines to kill cancer cells. Some of these medicines might also lower the body's defense system. In this study, patients will also get surgery and radiation, which are standard treatments to remove or shrink tumors. The study aims to see which chemotherapy plan works better and has fewer side effects. It will also check how well patients do in the long term and see if there are any effects on things like the ability to have children in the future.

• Study participation might last up to 5 years, with regular check-ups.
• Different medicine doses and schedules may affect side effects and outcomes.
• Patients may need to visit the hospital multiple times for treatments and tests.