Radioguided Occult Lesion Localization in the Breast

Until recently, noninvasive tumors such as ductal or lobular carcinoma in situ represented a relatively small proportion of diagnosed breast cancers. During the last decade, however, the widespread use of mammography has increased detection of preinvasive cancers; many authors indicate that 15% to 25% of diagnosed breast cancers are intraductal carcinomas, most of which are clinically occult (1)–(3). Over the next few years, the proportion of nonpalpable lesions is expected to exceed 50% of breast cancers (4)–(8).