Vincristine, Dactinomycin, and Cyclophosphamide With or Without Radiation Therapy in Treating Patients With Embryonal Rhabdomyosarcoma

DISEASE CHARACTERISTICS: * Diagnosis of embryonal rhabdomyosarcoma * Primary operation for pathological diagnosis within the past 42 days * The following variants are eligible: * Botryoid * Spindle cell * Anaplastic * Meets 1 of the following stage criteria: * Stage I, clinical group I or II (N0), defined by all of the following criteria: * Favorable site, including orbit, head, and neck (excluding parameningeal sites), genitourinary region (excluding bladder/prostate sites), or biliary tract * Tumor any size * Completely resected disease OR microscopic residual disease * Lymph nodes clinically negative * Stage I, clinical group III (N0), defined by all of the following criteria: * Favorable site * Tumor any size * Gross residual disease allowed (orbit only) * Lymph nodes clinically negative * Stage II, clinical group I (N0, Nx), defined by all of the following criteria: * Unfavorable site (any sites not listed as favorable sites) * Tumor ≤ 5 cm in diameter * Completely resected disease * Lymph nodes clinically negative OR lymph node involvement unknown PATIENT CHARACTERISTICS: Performance status * 0-3 Life expectancy * Not specified Hematopoietic * WBC ≥ 2,000/mm\^3 * Platelet count ≥ 100,000/mm\^3 * Hemoglobin ≥ 7.5 g/dL Hepatic * SGOT and SGPT ≤ 2.5 times upper limit of normal (ULN) * Bilirubin ≤ 2.5 times ULN * Bile acid ≤ 2.5 times ULN Renal * Creatinine based on age as follows: * \< 0.8 mg/dL (for patients \< 5 years of age) * \< 1.2 mg/dL (for patients 5-9 years of age) * \< 1.5 mg/dL (for patients ≥ 10 years of age) Cardiovascular * No severe heart disease Other * Not pregnant or nursing * Must have acceptable organ function for age * No uncontrolled infection * No other active malignancy * No other treated malignancy within the past 5 years * No hypersensitivity to study drugs * No Charcot-Marie-Tooth disease * No chickenpox PRIOR CONCURRENT THERAPY: Chemotherapy * No prior anticancer chemotherapy Endocrine therapy * Prior anticancer steroids allowed Radiotherapy * No prior radiotherapy Other * No concurrent pentostatin