Bicron targets PET applications for CurvePlate detector modules

Company sees promising growth in PET market

Scintillation crystal developer Bicron is shifting the focus of its curved-plate detector program to target PET applications rather than SPECT, according to an executive with the Newbury, OH, firm. Although the PET market at the moment is much smaller than SPECT, Bicron sees the prospects for growth in PET to be very promising, according to Mike Lopez, product manager at Bicron.

Bicron and parent company Saint-Gobain of France supply the lion's share of scintillation crystals to gamma camera developers through OEM arrangements. At the 1996 Society of Nuclear Medicine meeting, Bicron unveiled a new type of scintillation crystal, CurvePlate, that is curved rather than flat, as are conventional crystals. The company showed a mock-up of a curved SPECT detector head at last year's SNM meeting in San Antonio (SCAN Special Report 6/97).

Bicron believes that using a curved scintillation crystal rather than flat crystals can offer performance improvements, because a curved detector conforms more closely to the curvature of patient anatomy. Although the firm initially targeted SPECT applications, it has since found that CurvePlate may be more appropriate for dedicated PET uses, Lopez said.

For one, the development of curved collimators and protocols for CurvePlate would probably require a major R&D investment for only a marginal increase in SPECT performance. PET is a different story, however. The technology is based on coincidence events and thus does not require the use of collimators, removing this obstacle.

Research under way at the University of Pennsylvania in Philadelphia on the use of CurvePlate for PET applications has revealed additional benefits for the technology, Lopez said. The curved architecture appears to control light spread inside the detector head, restricting the phenomenon to a tighter group of photomultiplier tubes. In addition, gamma rays tend to localize closer to the entrance point of the crystal, making it easier to recreate coincident events. Both factors translate into better image resolution, Lopez said.

In addition to the work at the University of Pennsylvania, CurvePlate detectors are being evaluated by UGM Medical Systems, the Philadelphia-based developer of low-cost PET cameras. UGM president and CEO Gerd Muehllener is scheduled to give a presentation at the upcoming SNM meeting in Toronto comparing the performance of flat crystals with curved. Whether UGM develops a product based on CurvePlate is up to that company, Lopez said.

By shifting from SPECT to PET, there's no question that Bicron is targeting a far smaller market. According to a recent Frost & Sullivan report, the worldwide PET market was worth $48.7 million in 1996, while the global SPECT market was valued at nearly ten times as much, with $480 million in equipment sales. Bicron, however, sees much more potential growth in PET, due to the improving reimbursement environment for PET studies, rising interest in oncology imaging, and better distribution of fluorodeoxyglucose (FDG).

"I think there are 75 to 100 PET cameras out there, and probably around 5000 active SPECT or planar sites," Lopez said. "But you have to look at growth in the future, so that 75 can grow to 5000. It's hard to imagine 5000 growing to 20,000."

The PET market may also see the entry of new vendors with low-cost PET cameras based on sodium iodide detectors rather than more expensive bismuth germanate (BGO) crystals. Such a design is already used in UGM's camera, and Bicron believes that established PET companies with BGO-based products may be looking at developing sodium iodide cameras in the near future. ADAC Laboratories will take over rights to the UGM product from GE Medical Systems as of June 1.

"The big guys are trying to figure out if they need to come out with their own lower end dedicated PET cameras, too," Lopez said.

Bicron plans to emphasize CurvePlate in its booth at the SNM meeting, and is offering the detectors to any OEMs that would like to incorporate them into their PET cameras. In addition to the UGM paper, the University of Pennsylvania researchers will present a paper on the use of CurvePlate detectors in PET mammography imaging.