Workshop on the public health response to nasopharyngeal radium irradiation - September 1995

Morbidity and Mortality Weekly Report, March 29, 1996

During September 27-28, 1995, a workshop entitled "Public Health Response to Nasopharyngeal Radium Irradiation" was convened in New Haven, Connecticut, to address issues regarding possible adverse health effects of this former medical treatment. Workshop participants discussed the strengths and weaknesses of possible epidemiologic studies.

From 1940 through the mid-1960s, nasopharyngeal (NP) radium was used to treat hearing loss, chronic otitis, and other conditions in children and was used to treat aerotitis media in submariners and aviators in the military. The goal of this approach was to reduce swelling of enlarged lymphoid tissue, which was believed to be a cause of both hearing loss and aerotitis media. Treatment usually included insertion of an applicator with a capsule of radium through each nostril and placement of the radium near the eustachian tube opening for 8-12 minutes.

Workshop participants presented estimates of the numbers of persons treated and of the doses to nearby organs. An estimated 500,000-2 million persons may have received NP radium treatments. Radiation doses to nearby organs were estimated on the basis of bilateral use in an adult of 50 mg of radium sulfate in a 0.5-mm platinum capsule for 12 minutes per session for three sessions. Estimates were 2000 rads to local tissue, 24 rads to the pituitary gland, 5 rads to the brain, and 2 rads to the thyroid.

Based on a cohort study in Maryland of 904 exposed and 2021 unexposed persons during 1943-1960, the risk for all head and neck cancers combined was higher among persons who had received the treatment than among persons who had not (1); however, this finding was based on small numbers of cancers (three brain and one soft palate cancer) and was statistically significant only after categories were combined. A cohort study in the Netherlands of 2510 exposed and 2199 unexposed persons did not document a statistically significant increase in head and neck cancers in the exposed group (2). Follow-up studies of both cohorts are under way.

A panel of medical and public health experts and representatives of veterans' and civilians' groups then discussed and provided comments for a workshop report. The report encouraged CDC and the U.S. Department of Veterans Affairs (VA) to collaborate rate on the following public health activities:

1. Continue the follow-up studies of existing cohorts, and if possible, combine the data from these studies, include noncancer endpoints in the follow-up studies, and evaluate the results of the follow-up studies before considering an additional cancer incidence study of persons who received NP radium treatments. Although studies of persons who self-report exposure to the treatment are useful in generating hypotheses, such self-reporting should not be the means of identifying formal "case-subjects" in epidemiologic studies.

2. Veterans who received NP radium treatments should be provided access to the Ionizing Radiation Registry maintained by the VA and to priority medical care at VA medical facilities.

3. Rather than screening asymptomatic persons, physicians should be educated about how to obtain more complete and accurate histories from patients who received NP radium treatments. Subspecialists should be provided specific information about NP radium exposure. Reported by: J Stolwijk, PhD, A Saftlas, PhD, Dept of Epidemiology and Public Health, Yale Univ School of Medicine, New Haven. ML Fleissner, DrPH, Connecticut Dept of Public Health. Association of State and Territorial Health Officers, Washington, DC. S Mather, MD, Office of Public Health and Environmental Hazards, US Dept of Veterans Affairs. Radiation Studies Br, Div of Environmental Hazards and Health Effects, National Center for Environmental Health, CDC. Editorial Note: Nasopharyngeal radium was one of several radiation treatments used to treat benign conditions before 1950. Other approaches included use of external x-irradiation to treat hearing loss, acne, tinea capitis, and enlarged thymus, and the use of radon and radium to treat hemangiomas (3-7). When radium treatments were developed and used, other options were either not available, were considered more invasive, or involved external irradiation. Following the publication during the 1950s of findings regarding long-term effects of radiation, health-care providers reserved therapeutic radiation only for serious or life-threatening conditions.

Because most of the radiation from NP radium was in the form of beta particles, the highest dose was delivered to the soft tissue of the nasopharynx, in which the background rate of cancer is low (0.6 per 100,000 persons) (8) and which has not been documented to be a sensitive to radiation as thyroid or brain tissue.

In collaboration with workshop cosponsors, CDC plans wider published dissemination of the proceedings of the workshop. The VA is seeking legislation to provide veterans who received NP radium treatments with access to the VA Ionizing Radiation Registry and priority medical care at VA medical facilities. CDC, VA, and the Association of State and Territorial Health Officers are developing a live satellite videoconference for physicians on NP radium, which will be aired on September 5, 1996, from 12:30 p.m. to 2:30 p.m. eastern daylight time.