Background: Clinically occult breast lesions are found with increasing frequency as a result of the widespread use of mammographic screening.
Methods: This study reports a new localization technique in which a small quantity of 99mTc-labelled colloidal albumin is inoculated directly into the lesion under stereotactic-radiographic or ultrasonographic guidance. Correct positioning of the inoculum is checked by scintigraphy. A gamma ray detection probe is then used to locate the lesion and guide its surgical removal. The results of this method in 30 patients were compared with those obtained using the established hook wire method in another 30 patients.
Results: In the wire localization group, the mean(s.d.) distance from the lesion centre to the specimen margin was 24.5(0.4) (range 15-45) mm. For the radioguided group the figures were 13.8(0.3) (range 5-25) mm. The mean(s.d.) lesion concentricity (difference between the maximum and minimum distance from the lesion border to specimen margin) was 6.2(0.4) (range 2-15) mm in the wire localization group and 3.8(0.2) (range 1-10) mm in the radioguided group.
Conclusion: Use of a gamma probe allowed rapid, easy and accurate removal of occult breast lesions. In comparison to the hook wire method, radioguided removal allows reduced excision volume and better lesion centring within the specimen.