Use of capoten after total body irradiation prior to bone marrow transplantation reduces radiation-induced damage in tissues including the kidney and may form the basis for broader prevention efforts for radiation-induced damage, according to an article published online October 27 by the International Journal of Radiation Oncology, Biology and Physics.

In the current study, researchers randomized 55 patients (52 adults, 3 children) to the angiotensin-converting enzyme inhibitor or to placebo beginning three weeks after total body irradiation. At one year, both serum creatinine level and glomerular filtration rate favored capoten; furthermore, one-year survival was better for patients given capoten. All trends narrowly missed statistical significance.

Patients had all received care from July 1998 to January 2006 at Froedtert Hospital and Children's Hospital of Wisconsin, both major teaching affiliates of the College.

"The research holds promise, not only for protection of healthy tissue during radiation therapy, but also because it may lead to strategies for protection from radiation injury after nuclear accidents," says Eric P. Cohen, MD, professor of medicine in the division of nephrology and principal investigator for the study. "Our findings overturned the former dogma that normal tissue radiation injury is untreatable."

Kidney failure is a well known and serious complication of bone marrow transplantation and occurs in up to 50 percent of patients within the first 30 days after transplantation, increasing early mortality. Chronic kidney failure is also common and affects the health and well being of people otherwise cured of the cancer for which the transplantation was performed.

Because capoten can cause leukopenia, the study drug was not started until the new marrow had engrafted.

"The three-week delay in administration of the drug was justified by our animal studies in the late 1990s which showed that a delayed start of captopril could successfully prevent radiation injury to the kidney," said Cohen.

"In an earlier 1992 animal study, published in Radiation Research, we found that captopril was effective in treating chronic kidney damage and its progression after total body irradiation. That showed that normal tissue radiation injury can be treated," he said.