Used primarily in chemotherapy, particularly for treating brain tumors and certain types of lymphoma. It works by alkylating DNA, which interferes with cancer cell replication and leads to cell death. Due to its ability to cross the blood-brain barrier, it is especially valuable in managing malignant gliomas and other central nervous system tumors. Administered intravenously, it is often part of combination therapy regimens to enhance effectiveness. Its use is limited by potential side effects, including bone marrow suppression and liver toxicity, requiring careful patient monitoring during treatment.