The average age at which germ cell tumors of the brain present is around the onset of puberty. However, some will present in infancy and early childhood, and others present in adult life. The age at onset is important in that younger, pre-pubertal children will experience more profound damaging effects of radiation therapy - and such younger children are usually the very ones that harbor the most malignant types of CNS germ cell tumors that require more aggressive treatments in order to cure them. The germ cell tumors of the brain represent less than 5% of childhood brain tumors, and yet are also one of the most curable of brain tumors, being exquisitely sensitive to both radiation therapy and chemotherapy. However, their very rarity, and the complex heterogeneous forms they take, has led to a poor understanding of these tumors and how best to diagnose them and treat them. Debates ensue as to when surgery should be used for these tumors, when radiation therapy should be used alone or in combination with chemotherapy (and what doses and fields of irradiation should be used), and when can milder forms of chemotherapy suffice as opposed to more intensive chemotherapies. |