Arsenic Trioxide With MAPK Inhibitors and Chemotherapy for Stage 4/M Neuroblastoma

Inclusion Criteria: 1. Patients with a pathological diagnosis of neuroblastoma. 2. Preoperative staging as INRG M stage or postoperative staging as INSS stage 4 (regardless of risk classification). 3. Age ≥18 months and ≤18 years. 4. Informed consent obtained from the legal guardian, and signed informed consent form. Exclusion Criteria: 1. Patients with a history of other tumors who have received chemotherapy and abdominal radiation therapy. 2. Severe progressive or persistent heart failure: NYHA heart function class III or IV, or left ventricular ejection fraction (LVEF) \< 50%. 3. Severe progressive or persistent renal failure: glomerular filtration rate (GFR) \< 30 ml/(min·1.73 m²) or serum creatinine \> 5 mg/dL (442 μmol/L). 4. Severe liver dysfunction: aspartate aminotransferase (AST), alanine aminotransferase (ALT) ≥ 5× upper limit of normal (ULN), or serum total bilirubin ≥ 3× ULN.