Prospective data confirming the technical validity of image-guided needle biopsy of suspicious breast cancer lesions using Positron Emission Mammography (PEM) guidance has been published in the March/April issue of the Breast Journal.
Molecular imaging, using PET, has become an integral step in the evaluation of many patients with malignancy. However, its use in patients with breast cancer has been limited by the lower levels of 18F-FDG uptake in some breast malignancies compared to other cancers, the small size of many breast cancers and the need for biopsy under PET guidance. High-resolution breast PET, or PEM, with biopsy guidance software, can address these issues, according to the Judith E. Kalinyak MD, PhD, from Naviscan (San Diego), and colleagues.
The main objective of the study was to confirm successful targeting and lesion sampling. A second objective was to confirm safety and patient comfort during the procedure. Six physicians, using three different commercially available vacuum-assisted biopsy tools, conducted this study at five sites. The study used Naviscan’s high-resolution breast PET scanner, otherwise known as a PEM scanner.
Nineteen subjects underwent a total of 24 PEM-guided biopsies. All lesions were successfully targeted and sampled as determined by post-biopsy image scan evaluation, specimen imaging and pathologic concordance. Invasive cancer was identified in 13 of 24 lesions (54 percent), while four (17 percent) were high-risk lesions with three of these upgraded to malignancy at excision, according to Kalinyak and colleagues.
No serious adverse events occurred and all patients found the procedure to cause only minimal to mild discomfort. High-resolution PEM-guided breast biopsy is both safe and effective for the sampling of PET-depicted breast lesions, concluded Kalinyak and colleagues.
"PEM-guided biopsy is quite elegant and confers several advantages over MRI-guided biopsy," stated Wendie Berg, MD, PhD, breast imaging consultant at American Radiology Services, Johns Hopkins Medical Institutions at Green Spring, Lutherville, Md., a co-author of the paper. "We can easily image the breast after sampling to assure removal of the target, and resample at the same setting if needed.” PEM allows physicians to directly image the specimens, which both further confirms successful sampling and allows them to direct the pathologist's attention to the 'hot' specimens, Berg added.