First-line Chemotherapy With Temozolomide Alone for Non-enhancing Adult Brainstem Gliomas, With a Diffuse Subtype and Showing Clinical and/or Radiological Infiltrative Pattern of Progression

This phase 2 study is a prospective cohort study. Chemotherapy alone will be proposed to adult patients suffering from a "low grade" brainstem glioma subtype showing infiltrative, non-threatening clinico-radiological progression. Patients will receive temozolomide at a monthly standard dose of 150-200 mg/m2/j J1-J5, will be clinically evaluated every month and will undergo radiological evaluation every 2 months. The duration of treatment will be 12 months. Then, the patients will be followed-up until progression, with clinical evaluations and MRI performed every 2-3 months. At the time of recurrence, treatment with focal radiation therapy will be administered (54 Gy in classical fractions).