Radiotherapeutic studies with amifostine (Ethyol).

Radiotherapeutic studies with amifostine (WR-2721; Ethyol, US Bioscience, Inc, West Conshohocken, PA) are reviewed, with evidence that it offers clinical normal tissue protection and no evidence of any tumor protection. Conducting clinical trials with amifostine has been difficult because of the unique (toxicity) endpoints and concerns about tumor protection. The Radiation Therapy Oncology Group has conducted phase I studies and a phase II hemibody study, and is now in the process of conducting phase III amifostine studies. Amifostine remains the most promising compound for testing clinical radioprotection, and as new techniques are developed in radiation therapy to deliver higher doses of radiation, the protection of normal tissues will become even more important. This review will cover both the preclinical and clinical studies involving the use of amifostine with radiation therapy.