Breast-specific gamma imaging spots occult ca.(NEWS)

CHICAGO -- Breast-specific gamma imaging can detect unsuspected, additional breast cancers missed by mammograophy and physical examination in women with newly diagnosed breast cancer.

In a retrospective study in 159 women with at least one biospy-proven cancer, a follow-up breast-specific gamma imaging (BSGI) study identified clinically and mammographically occult cancer in 14 of 45 lesions that were biopsied because of BSGI findings. Nine of the 14 occult cancers of 64% were located in the same breast as the index lesion, principal investigator Dr. Rachel F. Brem reported at the annual meeting of the Radiological Society of North America.

"That's very important because the surgical management is going to be dependent on whether there is one breast cancer or more than one cancer in that breast or in the other breast," Dr. Brem told reporters at a press briefing. In at least one case, the discovery of an additional lesion meant that a mastectomy had to be performed rather than a lumpectomy as originally planned.

Unlike other adjunct imaging modalities such as mammography and ultrasound that image the physical structure of the breast, BSGI is a form of molecular imaging that captures the cellular functioning of the breast tissue through radiotracer uptake. Uptake of the radiotracer is proportional to the blood flow and mitochondrial activity in the breast. Cancerous cells show increased radiotracer uptake because of their higher metabolic activity.

"This fundamentally different approach to breast cancer diagnosis gives us the opportunity to diagnose more cancers," Dr. Brem said in an interview.

Previous studies using BSGI have shown that the technique improves cancer detection in high-risk women and can detect the earliest breast cancers, even those as small as 1 mm, said Dr. Brem, director of breast imaging and intervention, George ...