In addition to standard treatment (radiotherapy and temozolomide chemotherapy) the effects of two further drugs, which have been applied to millions of children and adolescents in other indications, will be compared to each other. The aim of the trial will be to investigate whether these drugs may increase the effects of radio- and chemotherapy, resulting in a better survival of the treated patients. One of these additional drugs will be valproic acid, traditionally used for treatment of seizure disorder. The other drug will be Chloroquin, a well-established drug for Malaria treatment. Recently, scientific studies provided evidence for anti-tumoral effects of both drugs: Valproat seems to be a so-called histondeacetylase inhibitor (HDAC inhibitor), controlling important genetic processes of tumor growth. Chloroquin is an autophagy inhibitor. It prevents the shutting-down of tumor cell metabolism, a strategy to ensure survival of the whole tumor by developing a resistance against radiation and antineoplastic agents.