New agent shows promise in scintigraphic breast imaging

An investigational radiopharmaceutical agent for scintigraphic breast imaging is safe and effective, and it could prove useful for monitoring cancer treatment response, according to a study from Scandinavia.

The agent, technetium-99m NC100692, is a small peptide that binds to integrin receptors during stages of tumor angiogenesis. This agent could provide valuable physiological information about lesions.

Researchers at the Karolinska Institute of Stockholm and the Norwegian Radiumhospital in Oslo tested the radiopharmaceutical in a nonblinded study of 16 patients with suspicious mammograms and four patients with benign breast lesions. All lesions measured 6 mm or more.

Imaging results were compared with pathology reports, and the research findings were published in the September Journal of Nuclear Medicine.

Twenty lesions were evident on mammography and ultrasound, while two cancers were picked up on pathology alone. Imaging with the new agent detected 19 out of 22 malignant lesions (86%). Missed lesions included one ductal carcinoma in situ and two cases of invasive lobular carcinoma.

No serious adverse events were encountered with the new agent, though mild side effects occurred in five patients, according to the study.

In publishing the results, the researchers noted that scintimammography has been performed with Tc-99m sestamibi to support mammography, but it has shown a sensitivity of just 50% for lesions less than 12 mm. In the new study, lesion size ranged from 5 mm to 40 mm, and Tc-99m NC100692 detected all lesions greater than or equal to 10 mm.

The researchers concluded that the new agent could potentially be used to assess whether chemotherapy treatment is working by assessing angiogenesis. It could play a similar role in other cancers.

For further information from the Diagnostic Imaging archives:

Breast-specific gamma imaging hunts for cancer

Adjunctive breast imaging modalities come up short

Technique adds dimension to nuclear mammography

Scintigraphy/mammography combo could replace biopsy in developing countries