Low-dose diagnostic X-rays do not appear to be a major cause of leukemia and other cancers of the blood and lymph systems, scientists said Wednesday.
The scientists, led by Dr. John D. Boice Jr. of the National Cancer Institute, examined X-ray records for 1,091 adults with leukemia, lymphoma and multiple myeloma and compared them a control group of subjects without cancer.The findings "confirm that diagnostic X-ray procedures are unlikely to be a major cause of leukemia, lymphoma, or myeloma in our society," the authors wrote in Wednesday's edition of the Journal of the American Medical Association.
Dr. Eugene Saenger, professor emeritus of radiology at the University of Cincinnati Medical Center, said the findings support previous studies.
Because radiation in large doses is known to cause cancer, the authors cautioned that despite their findings, "the potential hazards from radiologic examinations should be weighed against the medical benefits."
The scientists examined an average of 10 years of X-ray records for the patients, whose cancers were diagnosed between 1956 and 1982.
Only X-rays before the diagnosis, and only diagnostic procedures, such as chest X-rays and those used to identify broken bones, were examined. Therapeutic X-rays - much larger doses of radiation used to treat tumors - were not involved.