Figure 3 Timeline summary of all key events and toxicities. This patient was diagnosed with a high-grade glioma in early May of 2024 after anisocoria was noted upon admission for hypoxemia evaluation. Four days later, the patient underwent craniotomy for tumor resection, and 26 days after diagnosis, he began chemoradiotherapy. The first sign of toxicity manifested as grade IV platelet toxicity on day 36 of treatment, prompting discontinuation of temozolomide. However, 66 days after discontinuation of temozolomide, the patient’s platelet count had improved and maintenance chemotherapy was started. Unfortunately, a second sign of toxicity manifested as grade II platelet toxicity on day 28 of maintenance. A dose decrease was initiated on day 34 due to worsening thrombocytopenia. On maintenance day 40, the patient presented to the emergency department with severe epistaxis, which prompted a prolonged PICU admission and discontinuation of chemotherapy. On PICU day 37, the patient had a third sign of excessive toxicity, which manifested as brain MRI changes that were concerning for worsening post-radiation toxicity/necrosis. On PICU day 79, the patient’s brain MRI showed changes that were concerning for significant disease progression with uncal herniation. The patient\was compassionately extubated on PICU day 129 (272 days after diagnosis of the astrocytoma).