Naviscan hones PET to manage breast cancer patients

August 28, 2007

Naviscan PET Systems hopes to ride a building wave of interest in new breast imaging technologies with its high-resolution, small field-of-view positron system. The FDA-cleared device has obvious application as an adjunct in the diagnosis of breast cancer. But it may be able to do much more.

Naviscan PET Systems hopes to ride a building wave of interest in new breast imaging technologies with its high-resolution, small field-of-view positron system. The FDA-cleared device has obvious application as an adjunct in the diagnosis of breast cancer. But it may be able to do much more.

PEM (positron emission mammography) Flex Solo II offers an intrinsic resolution between 1.5 mm and 2 mm. But its greatest strength is its ability to characterize lesions metabolically and potentially spot malignancies at an earlier stage than any other technology.

Results from a pilot study of women with biopsy-proven breast cancer presented at the Society of Nuclear Medicine meeting in June indicate that the technology - with both sensitivity and specificity greater than 90% - is more helpful than MRI in preoperative planning. The study at the Center for Breast Care in Boca Raton Community Hospital in Florida documented that PEM was as sensitive as MRI in detecting invasive and noninvasive breast cancer and could identify pathologic atypia better than breast MRI.

"The clarity of the image is enabling the physician to make decisions sooner and with greater accuracy," said Sherri Antoniak, Naviscan vice president of corporate development.

Currently, physicians screen with mammography and ultrasound, and refer patients with suspicious lesions for biopsy. Recent studies have shown the value of using MR as an adjunct diagnostic aid. These modalities, however, require multiple interpretations, added expense, and lengthy evaluations, not to mention the invasive nature of needle biopsy or surgical excision.

"With PEM, we have seen in the preliminary data that hot spots can be indicated very quickly, in which case you can biopsy them and determine the stages of the cancer," she said.

Making this possible is a detector composed of thousands of 2-mm elements. This technology renders patient care more efficient and effective, Antoniak said. But rather than positioning the product strictly as a diagnostic aid, Naviscan hopes to carve out a niche in patient management. Because it may be possible to identify more, or even all, malignant lesions in the breast with the PEM Flex Solo II, physicians might be able to make better treatment choices using medication, radiation, and surgery.

In the future, PEM might be used to determine the efficacy of chemotherapy based on tumor response. PEM-based research could help identify the most effective treatments under specific conditions and provide a personalized approach to managing breast cancer patients, she said.

Achieving this potential will depend on a clinical trial that's scheduled for completion next year. Five medical centers are assessing the use of PEM and breast MRI in the presurgical staging of breast cancer.

Acceptance of the results, assuming they are positive, will be hastened by a widening recognition by the imaging industry that modalities other than mammography are needed in the fight against breast cancer. Adding to the credibility of PEM Flex Solo II is the success that PET/CT has achieved in oncology overall.

"Our focus right now is on the high-risk patient," she said. "But because we have a high-resolution, small-organ-specific device, perhaps down the road we will get into screening."