Radiation therapy for children with malignant lymphomas is usually limited to childhood Hodgkin's lymphoma. Radiation treatment is not used to treat non-Hodgkin lymphoma. Some acute childhood leukemia patients may require radiation to the brain or the brain in combination with the entire CNS axis. Total body irradiation may also be used for patients with leukemia as part of a stem cell transplantation.
There are detailed treatment protocols for radiation therapy for malignant lymphomas and leukemia. Radiation therapy is almost always given after, or in combination with chemotherapy. The protocols give clear guidelines for use of radiation therapy and information on what anatomical areas are suitable for radiation, as well as volumes and margins to the tumor area. Appropriate image diagnostics, dosage planning, radiation dosages and limits are also found in the protocols.
For Hodgkin's lymphoma, treatment is given according to the GPOH-HD-95 protocol. A new European protocol (EuroNet-PHL-C1) started in 2008 emphasizes reducing the use of radiation treatment in this patient group.
Radiation therapy is an effective treatment form and can improve the chance of long-term disease-free survival of Hodgkin's lymphoma patients. In some leukemia and non-Hodgkin lymphomas, radiation therapy to the brain or CNS axis may be part of the treatment for metastases to the central nervous system or be important in preventing metastases to that area. The risk for delayed damage in the child after radiation therapy (particularly growth disturbances, damage to radiated organs, or radiation-induced cancer) limits the use of radiation therapy to cases where it is absolutely necessary.
Radiation therapy is given at the University Hospital.
Very young children will require general anesthesia to complete the dosage planning and the necessary treatments (fractions). The dosage fraction (daily radiation dose) is most often in the range of 1.8–2 Gy and the total dose of radiation for Hodgkin's lymphoma is in the area of 20–35 Gy. The dosage depends on the size of the remaining lymphoma after chemotherapy and what organs are radiated. For total brain radiation or CNS axis, the total dose is in the area of 12-24 Gy. The dosages are significantly lower and the risk for delayed injury is much lower than after radiation therapy for most solid and CNS tumors in children.
Curative radiation therapy
Radiation therapy can be given as a part in the curative treatment plan for:
Hodgkin's lymphoma after chemotherapy according to protocol
Certain cases of acute leukemia according to protocol
Rare cases of non-Hodgkin lymphoma according to protocol or individual assessment
Palliative radiation therapy
- All patients with a local problem associated with growth of lymphoma or leukemia should be assessed for palliative radiation therapy. The plan general follows the same guidelines as the curative treatment plan with individual changes.