Nasopharyngeal radium irradiation: fundamental considerations.

Abstract

This article discusses the potential carcinogenic effects of radiation exposure from nasopharyngeal radium irradiation exposure and issues to consider when deciding whether to recommend screening for asymptomatic patients who have been treated by nasopharyngeal radium irradiation. The radiation exposure from the radium is primarily the result of gamma-rays, which are very penetrating. beta-Particles would affect only the tissues located within 1 cm of the eustachian tube orifice. On the basis of a quantitative risk assessment, the lifetime risk of brain cancer developing was estimated to be approximately 3 per 1000 persons, and the lifetime risk of a fatal cancer 5.6 per 1000 persons. When the medical benefits of screening asymptomatic patients are assessed, several factors, including the medical risks and benefits and cost-effectiveness of follow-up, should be considered.