Risk-Adapted Focal Proton Beam Radiation and/or Surgery in Patients With Low, Intermediate and High Risk Rhabdomyosarcoma Receiving Standard or Intensified Chemotherapy

"Dosage and route of administration:~* \< 1 year of age=0.025 mg/kg intravenously (IV)~* \> 1 year and \< 3 years= 0.05 mg/kg IV~* ≥ 3 years=1.5 mg/m\^2 IV. Maximum dose 2 mg in all participants."

"Dosage and route of administration:~* \< 1 year=0.025 mg/kg IV push~* ≥ 1 year=0.045 mg/kg IV push over 1 to 5 minutes."

"Dosage and route of administration:~During VAC chemotherapy:~* \< 3 years of age = 40 mg/kg IV~* ≥ 3 years of age = 1200 mg/m\^2 IV, with MESNA.~During maintenance for intermediate-risk participants:~* oral cyclophosphamide 50 mg/m\^2/dose/day (liquid or tablet)"

Surgery will be performed for the primary site tumor with the goal of removing tumor cells while maintaining function in the organ or adjacent organs involved.

Radiation therapy will be delivered at approximately week 13 (intermediate risk) or week 19 (high risk) after initiation of chemotherapy. Certain patients will receive radiation at week 4.

Dosage and route of administration: 15 mg/kg/dose/day IV.

Dosage and route of administration: 90 mg/m\^2/dose twice daily.

"If a participant's chemotherapy has been delayed or modified for hematologic toxicity, or if participant experiences a significant life-threatening toxicity due to bone marrow suppression, myeloid growth factor (either filgrastim or peg-filgrastim) will be given per institutional practice.~High Risk participants receive filgrastim 5 micrograms/kg/day (maximum 300 micrograms) subcutaneously beginning 24-36 hours after the last dose of chemotherapy. Continue at least 7 days, or until the ANC ≥750/µL whichever comes last. Sargramostim or peg-filgrastim may not be used."

"Clinical and/or imaging evaluation of regional lymph nodes will be conducted pretreatment and preoperatively as part of staging. This will aid in determining the efficacy of this procedure in defining involved lymphatics in at risk patients."

Dosage and Route Administration: During interval compressed therapy - irinotecan 50mg/m\^2 IV (maximum dose 100 mg/day) daily x 5.

Dosage and Route of Administration: During interval compressed therapy - Age \> 1 year: 1800 mg/m\^2/day IV x 5 Age \<1 year: treat with 50% doses calculated on a m\^2 basis.

"Dosage and Route of Administration:~Age \>1 year 100 mg/m\^2/day IV x 5 Age \< 1 year treat with 50% doses calculated on a m\^2 basis"

Dosage and Route of Administration: Used in substitution for etoposide in participants who experience allergic reaction. It will be administered 100 mg/m\^2/day IV.

"Dosage and route of Administration:~Age ≥1 year, 37.5 mg/m\^2 IV over 1 hour x 2 days Age \<1 year, 18.75 mg/m\^2 (i.e., a 50% dose reduction) IV over 1 hour x 2 days."

"Dosage and Route of Administration: Dexrazoxane dose should be 10x that of doxorubicin.~Age ≥1 year, 375 mg/m\^2 IV over 15-30 minutes Age \<1 year, 187l.5 mg/m\^2 (i.e., a 50% dose reduction) IV over 15-30 minutes."

Participants receive \^1\^1C-methionine to relate the distribution, intensity and change in \^1\^1C-methionine CTPET imaging of the primary site to tumor control and patient outcome.