Germ cell brain tumors are very rare, accounting for less than 5% of all brain tumors in children. This is a case of cured suprasellar germ cell tumor by whole brain radiotherapy complicated by leukoencephalopathy, radiation angiopathy and further stroke.
Note an absolutely symmetric changes (both calcifications and leukoencephalopathy, there are a few published similar cases) even if you don't know the patient's history you can to find a key a priori - it could be post-treatment changes as we see in this case.
Childhood stroke is another entity, it can be an outcome of paraneoplastic syndrome, chemo- and/or radiotherapy, vast majority of infections, varicella zoster more frequently including in the context of immunosuppression. We think the cause of stroke in this patient was a post-radiotherapy leukoencephalopathy and angiopathy because chemotherapy was not performed.