PET-based system focuses on breast lesions

Capping two years of development, Naviscan PET Systems of San Diego launched at the 2006 RSNA meeting a second generation of its PET product line, PEM Flex Solo II. The compact high-resolution scanner is optimized to assess breast lesions metabolically, although it could image other small body parts.

With its dual-plate flat-panel detector fixed at the end of an articulated arm, the improved Solo applies gentle compression to isolate and immobilize the breast. The pair of lutetium-based scintillation detectors provide a 17 x 24 cm field-of-view.

With Solo II, Naviscan has increased the depth of the detectors' lutetium oxyorthosilicate crystals to 13 mm from the 10 mm depth seen in its previous PEM Flex product. Greater crystal depth provides high spatial resolution, 1.5-mm intrinsic spatial resolution, 2-mm in-plane resolution, and 5-mm between-plane resolution, which can reveal cancers as small as 1.5 to 2 mm, according to the company.

Reconfiguring the crystals also should reduce the radiotracer dose needed to produce high-quality diagnostic images, said Sharon L. Smith, vice president of sales and marketing. The company will begin clinical trials this quarter to test whether and how physicians might trade off scan time and dose. The company hopes to achieve a happy medium that allows low tracer dose and high-quality images so the scanner can be used to evaluate breast cancer in high-risk patients, she said.

Naviscan, founded in 1995, has been on the product commercialization fast track for the past 18 months. The increased commercial push came after Sanderling Ventures of San Diego and Mayo Medical Ventures, a for-profit arm of the Mayo Clinic, took a controlling interest in the company. Naviscan plans to carve out a niche for its product as an adjunct to magnetic resonance imaging and whole-body PET for staging or restaging breast cancer and for pre- and postsurgical evaluation of patients. PET centers, comprehensive breast centers, hospitals, and outpatient imaging centers have expressed interest in the technology, according to Smith.

Reimbursement could drive how the device is used, she said. The PEM Flex Solo II, therefore, may be used after a tissue diagnosis has been made; after an equivocal examination with mammography, ultrasound, or MRI; or before surgery to evaluate the extent of disease. It also may be used to assess tumor shrinkage in patients on neoadjuvant therapy, or to scan for disease recurrence in patients with breast implants.

"We have sites that are doing high-risk patients for out-of-pocket payment (for applications not yet reimbursed), because the doctors have developed confidence in the technology," Smith said.