Amifostine Reduces Radiotherapy Side Effects

By Will Boggs, MD

NEW YORK MAR 07, 2006 (Reuters Health) - Amifostine reduces the side effects of radiation therapy and increases complete response rates without protecting tumor cells, according to a report in the March 1 issue of International Journal of Radiation Oncology, Biology, Physics.

"Amifostine has been shown to be effective and safe in order to diminish radiotherapy-related side effects, wherever the radiated area," Dr. Andre Deeke Sasse from Cidade Universitaria, Sao Paolo, Brazil told Reuters Health.

Dr. Sasse and colleagues evaluated the efficacy of amifostine in diminishing radiotherapy side effects by conducting a systematic review and meta-analysis of 14 randomized controlled trials comprising 1451 patients.

In these clinical trials, amifostine consistently reduced radiotherapy-induced mucositis, esophagitis, proctitis, acute and late xerostomia, dysphagia, pneumonitis, cystitis, and dermatitis, the authors report.

Complete response rates were 81% better for patients using amifostine than for other patients, the results indicate. "This fact clearly demonstrates a selectivity of protection limited to normal tissues," Dr. Sasse said. "The benefits were extensive, demonstrated for radiotherapy in head and neck, thoracic, and pelvic tumors."

Relapse rates did not differ between patients using amifostine and other patients. Based on this result, the researchers conclude "that there is sufficient evidence to state that amifostine does not protect the tumor."

The incidences of grade 3-4 nausea and grade 3-4 emesis were more than twice as high among patients using amifostine as among patients not using amifostine, the report indicates. Amifostine use was also associated with an increased risk for transient grade 3-4 hypotension.

"The side effects were satisfactorily controlled with regular use of antiemetic medications and usual precautions, as recommended by the manufacturer," the investigators note.

"The studies that consistently showed reduction of radiotherapy-related side-effects used amifostine on a daily basis, 20 to 30 minutes before the radiation therapy, with a dosage of 500 mg/meter-squared or 340 mg/meter-squared," Dr. Sasse added. "Therefore, we recommend this therapeutic schedule."

SOURCE:

• Int J Radiation Oncology Biol Phys 2006;64:784-791.