The goal of this clinical trial is to use modified Brentuximab Vedotin+doxorubicin+vinblastine+dacarbazine+Rituximab(BV-AVD-R) regimen in Chinese Classical Hodgkin's Lymphoma(HL) children. The main questions it aims to answer are:

• [Overall Response Rate(ORR) :Complete Response(CR)+Partial Response(PR)]
• [progression-free survival (PFS), event-free survival (EFS) and overall survival (OS) at 6 months and 1 year.] Participants will be given modified BV-AVD-R regimen according to rapid early responders (RER) or slow early responders (SER) after 2 cycles.

This study is a prospective study with period from October 2022 to December 2024, and planned to enroll 44 children with newly diagnosed intermediate- and high-risk classical HL. All patients will undergo Positron Emission Tomography(PET)/Computed Tomography(CT) at the time of initial diagnosis and after 2 cycles of modified BV+R+AVD regimen to determine early response. Rapid early responders (RER) defined as CR after 2 cycles of therapy. Slow early responders (SER) defined as no CR (partial response (PR) or stable disease) after 2 cycles of therapy. Intermediate-risk patients were stage IA bulk/E, IB, IIA bulk/E, IIB, and IIIA. High-risk patients were stage IIB bulk/E, IIIA bulk/E, IIIB, and IVA/B.

The primary endpoints include ORR (CR+PR) and adverse events. The secondary endpoints include progression-free survival (PFS), event-free survival (EFS) and overall survival (OS) at 6 months and 1 year.

Inclusion Criteria:

1. Age ≤ 18 years old, regardless of gender;
2. According to the WHO classification criteria in 2016, pathologically confirmed classic Hodgkin's lymphoma is immunohistochemical CD30 positive;
3. Newly diagnosed classic Hodgkin's lymphoma: all stages
4. The main organs function normally and meet the following definitions:

Blood routine examination: neutrophil count ≥ 1.5 x 109/L, platelet count ≥ 75 x 109/L, hemoglobin count ≥ 80 g/dL; Liver and kidney function: AST and ALT ≤ 2.0 upper limit of normal values; Bilirubin ≤ 2.0 mg/dL; Creatinine clearance rate ≥ 60 mL/min; 5) Functional status

• For patients aged 1-16, the Lansky score is ≥ 60 points.

• For patients over 16 years old, the Karnofsky score is ≥ 60 points. 6) Previous treatment

• Except for emergency mediastinal irradiation (<1000cGy) due to superior vena cava (SVC) syndrome, Hodgkin's lymphoma guidance treatment was not allowed before.

  8) Informed consent

• Patients or their legally authorized guardians must have a thorough understanding of their illness and the nature of the study (including foreseeable risks and possible adverse reactions), and must sign an informed consent form.

Exclusion Criteria:

1. Karnofsky<60% or Lansky<60% for individuals under 16 years old.
2. Children with Hodgkin's lymphoma who have received other chemical and radiation treatments.
3. Initially rated as low-risk pediatric classic Hodgkin's lymphoma (IA, IIA, without large masses)