Scintimammography for the detection of breast cancer.

Scintimammography is a functional imaging technique whereby radionuclide tracers in the patient's breasts are observed with a radiation-detection camera (gamma-camera). Tracers are designed to accumulate in tumors more than in healthy tissue; the most common tracers used to date are Tc-99m sestamibi and Tc-99m tetrofosmin. Scintimammography is useful in some clinical indications as an adjunct to mammography and to reduce the rates of negative biopsies, and it is recommended for lesions where additional information is required to reach a definitive diagnosis. Patients with equivocal mammograms may benefit from this test, as well as women with dense breasts and those with implants, since scintigraphy is not affected by breast density and the photons arising from the radiotracer are not overly attenuated by implants. Scintimammography is also of value in patients with locally advanced breast cancer, for monitoring and predicting the response to neoadjuvant chemotherapy. The near availability of high-resolution breast-dedicated cameras will allow the suboptimal sensitivity in detecting cancers of less than 1 cm to be improved; this is currently the main limitation of scintimammography. These new devices also have the potential to increase the number of breast scintigraphies performed and the role of nuclear medicine in breast cancer imaging.