For children up to 18 years with non-Hodgkins B-cell lymphoma, treatment is according to the European protocol BFM 04. The treatment takes place at regional hospitals only.
Treatment consists of 2-7 blocks with abbreviations A, AA, AAZ, B, BB, BBZ and CC. All of the blocks last for 5 days, except for the blocks given to children with B-cell lymphoma with primary CNS infiltration, which last for 6 days. A minimum of 16 days should pass between blocks.
There are 4 risk groups. The risk groups are determined based on stage, LD values, extent of tumor resection, and CNS infiltration. Children with primary CNS infiltration and children with primary mediastinal B-cell lymphoma are excluded from the risk group categories and are treated on their respective protocols.
Children in risk groups 3 and 4 receive higher doses of methotrexate with a longer infusion time. This leads to more intense side effects and longer periods of neutropenia than risk groups 1 and 2. Immune suppression and severe mucositis is a significant problem for B-cell lymphoma treatment and can lead to a prolongation of treatment (8).
Cytoreductive preliminary phase
Children with B-cell lymphoma are often very ill at the time of the diagnosis. It is crucial to start treatment as soon as possible, even if the diagnosis is unclear. It is especially important to intiate treatment if the child presents with thoracic infiltration or spinal cord compression. Treatment should start with a cytoreductive preliminary phase lasting for 5 days. By starting with the preliminary phase, the chance of tumor lysis syndrome is reduced.
Risk group 1 does not have preliminary phase treatment.