Ms. Lillian Gill, Senior Associate Director of the Center for Devices and Radiological Health (CDRH), provided an update on issues previously discussed by the Committee. The first was wireless cell phones, and she reported that CDRH had established a cooperative research and development agreement (CRADA) with the Cellular Telephone Industry Association. Under this agreement CDRH provides scientific oversight to research proposals dealing with the issue of radio frequency emissions from wireless phones.
Ms. Gill next updated the Committee on the issue of proposed amendments to the laser standard, which are intended to harmonize the FDA laser standard with the International Electrotechnical Commission (IEC) standard. The FDA has published a notice stating that laser devices should be in compliance with the IEC standard while the FDA standards are being amended. Those working on the FDA laser amendments are collaborating with FDA economic analysts to assess the economic impact of the proposed standard on industry.
Ms. Gill discussed the proposed amendments to the federal performance standard for fluoroscopic equipment. An analysis of the projected benefits of the amendments was presented at the 2001 FDA Science Forum, and it was included in a Notice of Proposed Rulemaking (NPR)
published December 10, 2002, in the Federal Register.
Ms. Gill also noted a number of activities in the area of counterterrorism and response to radiological threat in the wake of the September 11 tragedy. Because of a relatively large concentration of expertise in CDRH on domestic radiation emergencies, the Center has provided training for personnel in other FDA centers and PHS agencies via a basic course in radiation physics. A cadre of Center personnel will provide support to regional and field offices and handle communication with the public in case of domestic radiation emergencies.
For the first formal presentation, Dr. Stanley Stern of CDRH discussed how the interplay of technology and clinical practice in computed tomography (CT) raises public health concerns over increased CT use. He discussed CT dosimetry and recent technological evolution of CT systems. He then described general public health concerns regarding the overall CT dose to the population, CT exams of children and small adults, self-referrals for asymptomatic CT screening, and CT fluoroscopy for interventional procedures.
Dr. Stern explained that the FDA is considering the possible development of additional CT equipment performance standards. These standards would require technically feasible features to reduce patient dose, such as displaying or recording a standardized dose-index, for the purpose of quality assurance audit, implementing a means of automatic exposure control based on patient size, and using more precise collimation of the primary beam to limit inefficient x-ray field sizes in multi-slice CT systems. When fully implemented, such standards are projected to reduce collective dose on the order of 200,000 person-sieverts annually. A framework of issues for analysis has been established to develop a concept paper for CDRH decisions on how to proceed, and the involvement of industry and professional groups will be sought for their input.
Sunlamp Products was the next topic addressed. Dr. Howard Cyr of CDRH discussed areas where the FDA is considering moving forward with amendments to the regulations which affect these products. The first proposal currently being considered is a revision of the warning labeling required under 21 CFR 1020.40 for sunlamp products and ultraviolet lamps. The objective in changing the label is to provide clearer, user-friendly language. FDA also would propose that this new warning label be included in all catalogues, specification sheets, descriptive brochures, and with any other purchasing information pertaining to each sunlamp product or ultraviolet lamp.
FDA is also considering proposing that modification of a sunlamp product by any person be deemed manufacturing if such modification affects any aspect of the product's performance or intended function. Such modification would require manufacturer recertification and reidentification of the product in accordance with 21 CFR 1010.2 and 1010.3. Other aspects of these products which Dr Cyr discussed were possible changes to the requirements for the allowed spectral transmittance of protective eyewear and the issue of determining the compatibility of replacement lamps.
Following Dr Cyr's presentation representatives of sunlamp manufacturers and tanning salon operators addressed the Committee with their views regarding standardized measures of sun bed performance, sunlamp compatibility, the wording of warning labels and protective eyewear.
The final formal presentations concerned x-ray security screening systems. Mr. Frank Cerra of CDRH discussed the ANSI N43.17 consensus standard on radiation safety for such systems, which was adopted and approved in April 2002. He briefly described the operation of these backscatter imaging products and how they are evaluated.
Mr. Daniel Kassaday of CDRH followed Mr Cerra and began by discussing transmission x-ray products, which were not encompassed by the ANSI standard and which result in higher doses than backscatter devices. Proponents for these types of security systems have suggested that they have the potential for use by the commercial mass transportation industry, sports facilities, prisons, banks, or public buildings. Any added level of security thus provided would have to be weighed against the long term potential public health risks of repeatedly exposing large numbers of the population to ionizing radiation, to which they would not otherwise be subject.
Because such x-ray security screening systems are not medical devices, FDA does not clear or approve their use prior to marketing, and there currently is no federal performance standard that applies to these products. FDA is therefore suggesting that perhaps a guidance document should be developed for all types of these systems which would address radiation safety concerns. FDA also thinks that there may be a need to develop a mandatory performance standard that would specifically address these products, their performance aspects and the dosimetry issues.