Chemotherapy and Radiation Therapy Practice Test 2026 - Free Exam Questions and Study Guide

Amifostine acts as a radioprotective agent to reduce normal tissue toxicity. It is given before radiotherapy and is converted in normal tissues by alkaline phosphatase into an active thiol form that scavenges free radicals produced by radiation and helps stabilize DNA, thereby lowering radiation-induced damage to healthy cells. Because normal tissues preferentially activate and take up amifostine, it provides selective protection, which can lessen side effects such as xerostomia, mucositis, and nephrotoxicity without enhancing tumor kill. It is not used to increase tumor destruction, nor is it an analgesic or a vasodilator intended to improve perfusion.