Radiotherapy of malignant lymphomas.

Radiotherapy of non-Hodgkin's lymphomas situated in the central nervous system is basically similar to the treatment applied to any other part of the body. There are two requirements: the first is the prophylactic irradiation of the CNS in a systemic disease of the reticuloendothelial system mainly in acute lymphatic leukemia; the second is the treatment of solitary tumors in the CNS. Radiotherapy can improve dramatically the results obtained with intrathecal chemotherapy, particularly in leukemic involvement of the CNS in childhood. The fractionated single radiation dose should be increased slowly and total doses of 2 500 rd should not be exceeded. Prophylactic radiotherapy of the CNS in acute leukemia has to include the entire subarachnoid space. It is therefore necessary to irradiate the entire skull and spinal cord. This treatment schedule and its results will be discussed. There is a tendency to sue prophylactic radiotherapy in other systemic diseases of the RES as well. The indications and contraindications for this will be discussed. The methods and results of treatment of focal lesions with regard to the morphologic tumor pattern are discussed. Rare primary tumors of the CNS which have the histological features of lymphoma-sarcoma or reticulosarcoma have the best prognosis as far as radiotherapy is concerned.