Nimustine Hydrochloride is primarily used in the treatment of various types of cancer, particularly brain tumors such as glioblastoma and malignant lymphoma. It functions as an alkylating agent, which means it works by interfering with the DNA of cancer cells, preventing their growth and replication. This makes it effective in slowing down or stopping the progression of these diseases. It is often administered intravenously or intra-arterially, depending on the specific condition being treated. Due to its potent nature, it is typically used in combination with other therapies to enhance its efficacy. However, its use is carefully monitored due to potential side effects, including bone marrow suppression, which can lead to reduced blood cell counts.