Radiation Risk of Mammography

Abstract

No woman has ever been shown to have developed breast cancer as a result of mammography, not eveeen from mulriple studies received over many years with doses higher than the current average dose to the current average dose to the glandular tissues of the breast of approximately 2.5mGy (250 mrad) (McLelland et al. 1991). However, the possibility to such risk has been raised because of excess breast cancers observed among populations exposed to much higher doses of 1–20 Gy (100–2000rad.). These mainly include Japanese A-bomb surviors (Katoand Schull 1982; McGregor et al. 1977; Preston et al. 1987; Preston and Pierce 1988; Shimizu et al. 1988, 1989; Tokunaga et al. 1979, 1984, 1987), North American tuberculosis sanatoria patients from Masschusetts (Boice et al. 1979; Hrubec et al. 1989) and Canada who underwent multiple chest fluoroscopies (Howe et al. 1982; Howe 1984; Hiller et al. 1989), women from New York State (Mettler et al. 1969; Shore et al. 1977, 1986) and Sweden (Baral et al. 1977; Mattson et al. 1993) treated with radiation therapy for benign breast conditions such as postpartum mastitis, infants treated in New York State for thymic enlargement with radiation therapy (Hildreth et al. 1989), and women who had been treated in California with radiation therapy for Hodgkin’s disease (Hancock et al. 1993). This chapter will estimate the hypothetical risk from mammography based on the latest radiation risk estimates provided by the National Academy of Sciences-National Research Council Committee on the Biological Effects of Ionizing Radiation (BEIR V Committee 1990) and compare such risk to the projected benefits from screening.