The goal of this clinical trial]is to evaluate the efficacy, safety and feasibility of radiotherapy combined with Realgar-Indigo naturalis formula（An oral arsenic agent）in the treatment of rhabdomyosarcoma in children. Including the occurrence of adverse events and the improvement of quality of life.

Inclusion Criteria:

• Eastern Cooperative Oncology Group performance status score（ECOG PS）: 0-2, and the expected survival time is ≥3 months;

• At least one measurable lesion according to RECIST version 1.1;

• Postoperative pathological diagnosis of rhabdomyosarcoma, pathological staging of Group II-III patients;

• Patients who have not previously received radiotherapy, have received chemotherapy or whose legal guardian refuses to receive chemotherapy, and may have received surgical treatment for the initial diagnosis;

• Normal major organ function, i.e., meeting the following criteria:

  1. Blood routine examination standards shall meet:(No transfusion within 14 days)

     1. Hemoglobin(HB)≥90g/L;
     2. Absolute Neutrophil Count（ANC）≥1.5×109/L;
     3. Platelet count(PLT)≥80×109/L

  2. Biochemical examination shall meet the following standards:

     1. Bilirubin（BIL）<1.25 times the upper limit of normal (ULN);
     2. Alaninetransaminase(ALT) and aspartate transaminase（AST）<2.5 ULN;
     3. Serum creatinine≤1ULN, endogenous creatinine clearance 50ml/min (Cockcroft-Gault formula)

• The subject voluntarily participates in the study, and the patient or legal guardian signs the informed consent form with the consent of the patient, with good compliance and cooperation in follow-up;

• Patients whose physician believes the treatment will benefit.

Exclusion Criteria:

• Previous or concurrent with other malignancies;
• Persons who have been proved to be allergic to Realgar-Indigo naturalis formula and/or its excipients;
• Has a number of factors affecting oral medication (such as inability to swallow, nausea, vomiting, chronic diarrhea and intestinal obstruction, etc.) ;
• Abnormal coagulation function (international normalized ratio(INR) > 1.5, Activated Partial Thromboplastin Time(APTT) > 1.5 uln) , the patients with bleeding tendency (such as active ulcer lesion in stomach, occult blood in stool (+ +) , black stool and/or hematemesis within 3 months, hemoptysis) or the lesion located near the great vessels;
• Tumors involving the skin and/or pharyngeal mucosa with ulceration;
• Have a history of psychotropic substance abuse and can not quit or have mental disorders;
• patients who had participated in clinical trials of other drugs within 4 weeks;
• The patients whose organ function had not recovered more than 35 days after the previous chemotherapy and could not be treated with the next course of chemotherapy;
• No other anti-cancer treatment may be used during radiotherapy except for the treatment prescribed in the protocol;
• According to the researchers' judgment, there are other patients with concomitant diseases that seriously compromise patient safety or affect the patient's ability to complete the study.