FDA Urges Caution in Choosing X-ray Devices
By Lou Anne Epperley, DVM
For Veterinary Practice News
Posted: April 25, 2012, 7:15 p.m. EDT
It looks so good on the Internet auction website: For around $875, you can own a “green” hand-held portable wireless dental X-ray unit! Shipped from Hong Kong, “This is an innovative Chinese design named the ‘Green X-ray Machine,’” the ad reads. “Safety is guaranteed. While using a small amount of radiation there is no need for protection.”
But in February, the U.S. Food and Drug Administration warned that the devices “may not be safe or effective and could potentially expose the user and the patient to unnecessary and potentially harmful X-rays.” The ad claims the machine is “FDA compliant.”
Policing equipment shipped directly from another country via the Internet is a work in progress, said Daniel Van Gent, MP, MS, the X-ray program manager for the Washington State Department of Health.
Because Washington state law requires newly purchased medical X-ray equipment to be inspected by his department before use, safety issues with the Green X-ray Machine ordered by a dentist were discovered and reported to the FDA.
“There is absolutely no way to determine on eBay whether the unit is manufactured by an FDA-approved manufacturer,” Van Gent said.
Since regulation of X-ray equipment varies from state to state, some veterinarians, doctors or dentists may be using the machine and be unaware of radiation risks to the patients and the operators.
Veterinarians use approved hand-held units for equine intraoral dental radiographs, said Rich Pfaff of Christian Icons & X-ray LLC in Springville, Ind.
“It is lightweight, plus offers the convenience of not having to deal with a power cord,” he said. “It does a very nice job, in particular when used with the intraoral plates.”
In an anesthetized patient, a hand-held unit allows a more precise aim of the X-ray beam without being fixed on an articulating arm, added J.K. Waldsmith, DVM, president of Vetel Diagnostics in San Luis Obispo, Calif.
All FDA-approved X-ray units must display this warning label.
The FDA’s investigation turned up the following, according to Steve Dawson, marketing manager for Aribex in Orem, Utah, manufacturer of the NOMAD hand-held X-ray: First, the issues seem to come from foreign manufacturers. Second, the purported illegal devices are being sold online.
And rather than the FDA logo, Dawson said, the equipment is required to bear specific compliance language and a specific warning label on the X-ray panel.
In testing the Green X-ray Machine, Van Gent said his state regulators noted that it lacked a phalange shield to protect the operator from X-ray Compton backscatter coming from the patient’s mouth during a bite wing X-ray procedure.
“We were measuring over 5,000 millirem per hour at 1 meter of distance,” he said, compared to the approved safe dose of radiation set at a maximum of 100 millirem per hour.
Moreover, if the kilovoltage potential of the machine’s X-ray photons is too low, the patient’s skin and eyes can get burned, Van Gent said, so the measured kvp must not vary from the dial setting by more than 10 percent. When investigators set the Green X-ray’s dial to 70 kvp, the actual measurement was 58 kvp, “so that was way out of tolerance, too,“ he said.
When shooting “soft” radiographs below 20 kvp, a device is required to have a 1.5-millimeter filter of aluminum or the equivalent, Van Gent added. “This machine has about 1.2 millimeters,” he said.
As a result, health department regulators gave the dentist who owned the new machine written notice not to use it because, “These units have not been cleared by or reported to FDA, [and] there is no evidence to show that they are safe and effective or that a quality control testing program has been followed, which may lead to the public being exposed to unnecessary radiation.”
The FDA notified U.S. import authorities and asked that the units be put on import alert and detained if found. But direct shipment can circumvent import officials, Van Gent said.
Meanwhile, Aribex’s Dawson said having an unethical competitor cast a shadow on the industry is frustrating.
“We have spent a lot of time and money having our units tested for safety,” he said of the NOMAD. “It’s rough for us because people think they’re the same, and they’re not.”
In bringing the hand-held portable X-ray to market, Dawson said Aribex first obtained FDA clearance for sale in the United States. The equipment was “groundbreaking,” he said, and the company also had to apply to every state for approval. Aribex is subject to scheduled and unscheduled FDA audits, he said. NOMAD is also certified by the International Standards Organization, he said.
“It’s very disappointing when someone comes in and tries to circumvent all the legalities we have to follow,” Dawson said.
Waldsmith, of Vetel Diagnostics, said his experience with regulators’ issues “has been more a function of state practice acts and radiation safety practices than actual products.” While hand-held X-ray devices may be allowed at the federal level, standards differ between states, he said.
“Vetel Diagnostics deals with three manufacturers of portable X-ray generators,” he said. “There’s certainly a lot of interest in them right now.”
Dawson said proper labeling, as displayed on the NOMAD, includes: “Designed and manufactured in compliance with IEC 60601-1, 60601-1-1, 60601-1-2, 60601-1-3, 60601-2-7, and DHHS Rules 21 CFR Subchapter J, applicable at date of manufacture.”
A warning label on the X-ray panel should state these exact words: “This X-ray unit may be dangerous to patient and operator unless safe exposure factors, operating instructions and maintenance schedules are observed.”
In short, Dawson said, the FDA’s challenge is “to find out who’s doing it, how extensive it is, and then take legal means to keep them from coming into the country. And that’s difficult.” <HOME>
Give us your opinion on
FDA Urges Caution in Choosing X-ray Devices
Industry Professional Site: Comments from non-industry professionals will be removed.