There are two additional treatment arms in addition to the four being compared. All children who have localized lymphoblastic lymphoma will be assigned to a treatment arm called Treatment A0. In addition, they will also be given radiation therapy to the head after chemotherapy has been completed. Only children with cancer in the brain or spinal cord will be given radiation to the head. At the time of study entry, children who do not have localized lymphoblastic lymphoma and do not have cancer in the brain or spinal cord will be randomized to one of the four treatments being compared.
Randomization means that the treatment arm to which a child is assigned is based on chance.
Neither the child's family nor the physician chooses which treatment arm a child will be given. A computer makes the assignment. Each child has an equal chance to be placed in any of the four chemotherapy treatments being compared. Each of the 4 treatment arms is made up of 5 phases of chemotherapy. In the middle phases, called consolidation, interim maintenance and delayed intensification, anti-cancer drugs are given to destroy any remaining lymphoma cells.