There is currently no standard approach to recurrent primary brain tumours. Treatment approaches will depend upon tumour histology, tumour location, prior therapy, patient's age and performance status, as well as patient and physician preference. Although a wide number of therapeutic options are available, some more commonly used and potentially beneficial treatments will be covered below for the more common adult CNS malignancies.
Primary brain tumours rarely develop systemic metastases. Occasionally, PNET’s can spread to bone or bone marrow and be detected on bone scan or bone marrow aspirate. More commonly, CNS tumours may spread within the neuraxis along the leptomeninges and into distant intra-parenchymal sites. Again this is most common among PNET’s but has been seen infrequently with ependymoma, malignant gliomas and pineal region tumours. Unfortunately, CSF seeding portends a poor prognosis and treatment is often limited to palliative radiotherapy to symptomatic sites. Chemotherapy may be beneficial in some patients with PNET and germ cell tumours but responses are rarely durable.