Radiotherapy and image management systems dominate FDA picks

The radiology pipeline was anything but encouraging in July, as the FDA cleared only 21 products. This was the second consecutive month that the number of 510(k) clearances dipped to around 20 (SCAN 8/8/01). Last year, the monthly numbers were in the high 20s throughout the summer, dipping to 21 in September, then rocketing back to near 30 in both October and November, as vendors prepared for the RSNA meeting. The slim pickings this summer may not affect new RSNA product releases if FDA activity picks up in the next few months. But reasons for concern involve more than just the low numbers.

The types of products being cleared do not represent the glamour modalities, which have fed industry growth over the last several years. Only one CT product cleared the FDA, and it appears to be an enhanced version of a previous model. The only MRI product among the July offerings was an enhancement. The sole ultrasound product was a handheld unit, although its development may signal a rising level of performance in this category. Teratech’s model 2000 features Doppler and harmonic imaging modes with transducer frequencies ranging up to 8 MHz, delivering frame rates up to 58 per second. Images are presented on a 15.7-inch liquid crystal display, an unusually large area for handheld products. The company cited the Acuson Sequoia and Aspen as substantially equivalent systems.

Radiotherapy products were the most popular of the July clearances, accounting for 45% of the group. Radiotherapy clearances included two turnkey radiation delivery systems. Image management products were close behind with 29%, which were mostly software packages designed to evaluate 2-D or 3-D images.

Two proton beam products, classified by the FDA as charged-particle radiation therapy systems, were cleared. Massachusetts General Hospital won FDA acceptance July 20 for its Northeast Proton Therapy Center. NPTC is designed to treat patients with localized tumors or other diseases susceptible to radiation treatment. The product, described by the hospital as a “facility,” produces and delivers a proton beam of known energy, intensity, and shape. It creates and directs the proton beam, produces a transverse and longitudinal dose distribution, and delivers the designated dose. The facility was judged substantially equivalent in function, character, and accessories to proton facilities operating at Harvard University and Loma Linda University.

Eight days earlier, Belgian firm Ion Beam Applications won FDA clearance for its Proton Therapy System. As with MGH, the Belgian firm cited the Loma Linda and Harvard devices as predicates for its system, noting that PTS is designed to treat patients with localized tumors and other radiosensitive conditions. PTS, like other such devices, may be configured to work with several rooms.

The other category, x-ray, featured a digital product, Smart Rad, developed by Israeli firm CMT Medical Technologies. The system uses the Pixium 4600, a flat panel manufactured by Trixell, a joint venture involving Siemens Medical Solutions, Philips Medical Systems, and Thomson Tubes Electroniques. The amorphous silicon-based solid-state detector is the cornerstone of Philips’ Bucky-Vision and Siemens’ Thorax FD and Multix FD. The Trixell detector has also been incorporated into Infimed’s StingRay digital upgrade for existing conventional radiography systems. Smart Rad will also likely be sold as an upgrade. Documents filed with the FDA indicate that the product will not include the x-ray system. Smart Rad will, however, ultimately be configured with the flat panel mounted in a bucky interfaced with the x-ray system, workstation, monitor, and laser imager. It will be used wherever conventional film-based systems are used for general radiography exams except fluoroscopy, angiography, and mammography.

Following are FDA-provided data on the other July clearances.

Radiotherapy

• ExacTrac 2.0 Novalis Body Module (Brainlab, July 31). The system positions patients at the isocenter of radiation delivered by a linear accelerator as part of stereotactic radiosurgery or radiotherapy. Results are based on an imported isocenter used by a planning system or simulator. ExacTrac 2.0 allows verification and, if necessary, correction of the patient’s position based on a comparison of reconstructed digital images calculated from a set of CT images that are used as the references, and real-time x-ray images. Structures on the images can be either anatomical landmarks or implanted internal markers. Corrections for some applications, such as the treatment of prostate tumors, may be achieved by using an ultrasound module, which compares the reference CT set with real-time ultrasound images.
• Immobilization System for ENT (Arplay Medical, July 12). The head immobilizer is used to constrain the head and neck of a patient during external-beam radiotherapy. It consists of a base plate, mesh, and U-shaped frame with pins affixed to the base plate. The plate typically is attached directly to the table or to a headrest that hyperextends the neck.
• Variseed 7.0 (Varian Medical Systems, July 12). The software package is used to evaluate patients with prostate cancer for permanent implant of radioactive seeds. It supports pre-, post- and intraoperative evaluation.
• Interstrand 125 and Interstrand 103 (IBT, July 12). The radionuclide brachytherapy sources are sealed in titanium and threaded onto absorbable polyglyconate monofilament sutures. The seeds, consisting of either iodine-125 or palladium-103, are used as primary treatment for prostate cancer or unresectable tumors or to treat residual disease after excising the primary tumor.
• Isoaid iodine brachytherapy seeds (Isoaid, July 10). The brachytherapy seeds, consisting of I-125, are sealed in titanium and are intended to treat selected localized tumors.
• Ameritek Brachytherapy Template (Ameritek Medical, July 17). The product guides biopsy and/or endocavity ultrasound needles, providing a fixed path along which the needle or probe travels to a site targeted by ultrasonography.
• RV-IVD Wireless Dosimeter model 1133 (Sun Nuclear, July 26). The monitor measures the radiation dose delivered to a patient using a linear accelerator or other radiation source, such as cobalt-60. It has three detector inputs per detector pod. As with other such devices, diodes serving as radiation detectors are connected to the detector module and then placed on the patient prior to the procedure. Dose measurements are transmitted by radio to a base station, which relays the data to a display module.

Image management

• Monochrome Perfectly Flat Panel Displays, ME Series (Totoku Electric, July 31). The display systems are designed for use with PACS. The three products in the series (ME221f, ME222f, and ME521f) differ in resolution (1200 x 1600 to 2048 x 2560 pixels) and in display area (width of 300 to 400 mm, height of 400 to 300 mm). Maximum luminance also varies.
• eFilm workstation (eFilm medical, July 31). The software package is one component of the company’s PACS. The product, which supports image viewing and manipulation, receives digital images and data from any digital modality, as well as secondary capture devices and imaging gateways. Images are stored, communicated, processed, and displayed on a local disk. Capabilities include adjustment of window width and level; image stacking; annotation and measurement of regions of interest; and inverting, rotating, and flipping images.
• QCU Analytical Software Package (Medis Medical Imaging Systems, July 31). The analytical software allows import and visualization of primarily intravascular ultrasound images, using CD-ROM and digital networking. Tomographic images of the lumen and arterial wall of coronary or vascular segments are analyzed using automated algorithms that detect contours, quantitate length and diameter of structures, and measure the area and volume of regions of interest. The package supports clinical diagnoses concerning stenosis, as well as the placement of interventional devices. Data may also be used in patient follow-up to evaluate the results of procedures, particularly stent morphology.
• Voxar VC, Model 1.0 (Voxar, July 12). The PC-based software displays 3-D reconstructions of CT and MR images as part of the process for screening and detecting colon polyps, cancers, and other lesions. The product processes and renders images for review, storage, printing, and DICOM distribution.
• Vortex (Ultravisual Medical Systems, July 12). A PC-based system that provides image storage, display, and workflow integration. The display architecture offers work group diagnostic viewing for radiologists, as well as image review for referring physicians and other clinicians. Images may be displayed in 2-D and 3-D, including volume rendering and multiplanar reconstruction for transmittal to Web-enabled viewers using local and wide area networks.
• TelePax (imed systems and consulting, July 11). The multimodality software, which runs on PCs using Microsoft NT or 2000 operating systems, includes three modules: TelePax-DVS acquires, stores, retrieves, transmits, and displays images that can be manipulated, reviewed, and printed using built-in algorithms; TelePax-AQS connects to imaging modalities to import or acquire images; and TelePax-HyperLink software communicates and transmits data between TelePax stations, optimizing transmission rates over standard phone lines.

MRI

• Infinion Enhancement Package (Marconi, July 19). Details not available.

CT

• SCT-7800TC (Shimadzu, July 3). The whole-body CT scanner has the same indications as its predecessor, SCT-7800T, which was commercialized in late 2000. This latest version includes a CT fluoroscopy option.

X-Ray

• UROlogic (PCK Electronic Industry and Trade, July 10). The urological table, featuring x-ray fluoroscopy, is designed around an undertable image intensifier. The system, for diagnostic and interventional procedures, consists of a floor-mounted tilting patient support table, x-ray generator, x-ray tube assembly, triple-mode image intensifier, and CCD-based television system. The tabletop moves longitudinally as well as laterally and can be tilted from -15° to +87°. Movement of the connected x-ray tube and image intensifier allows the operator to scan without moving the patient.
• Modified M-IV Mammography System (Lorad, July 11). The latest version of the M-IV, like its predecessor, is intended for both screening and diagnostic mammography.