Nitrosoureas use

Carmustine and lomustine are closely related nitrosoureas. Because of their ability to penetrate the CNS, the nitrosoureas are primarily employed in the treatment of brain tumors. They find limited use in the treatment of other cancers. [Note: Streptozocin is another nitrosourea that is specifically toxic to the β cells of the islets of Langerhans, hence its use in the treatment of insulinomas.]