Diagnostic X-Ray Equipment Performance Standard; Request for Comments and Information

DEPARTMENT OF HEALTH AND HUMAN SERVICES

Food and Drug Administration

21 CFR Part 1020

[Docket No. 97N-0427]

RIN 0910-ZA06

Diagnostic X-Ray Equipment Performance Standard; Request for

Comments and Information

AGENCY: Food and Drug Administration, HHS.

ACTION: Advance notice of proposed rulemaking.

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SUMMARY: The Food and Drug Administration (FDA) is announcing its

intention to propose amendments to the performance standard for

diagnostic x-ray systems and their major components. The agency is

taking this action to address changes in the technology and use of

radiographic and fluoroscopic systems. The agency is issuing this

advance notice of proposed rulemaking (ANPRM) in accordance with its

policy of early public disclosure of rulemaking activities. The FDA is

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soliciting comments and information from interested persons concerning

the subject matter of the proposed amendments.

DATES: Submit written comments on the proposed amendments by March 11,

1998.

ADDRESSES: Submit written comments to the Dockets Management Branch

(HFA-305), Food and Drug Administration, 12420 Parklawn Dr., rm. 1-23,

Rockville, MD 20857. See the SUPPLEMENTARY INFORMATION section for

electronic access to the summary of concepts for amendments and a

summary of the April 8 through 9, 1997, meeting of the Technical

Electronic Product Radiation Safety Standards Committee (TEPRSSC).

Submit written requests for single copies of the Diagnostic X-Ray

Equipment Performance Standard to the Division of Small Manufacturers

Assistance (DSMA), Center for Devices and Radiological Health (HFZ-

220), Food and Drug Administration, 1350 Piccard Dr., Rockville, MD

20850. Send two self-addressed adhesive labels to assist that office in

processing your request or fax your request to 301-443-8818.

FOR FURTHER INFORMATION CONTACT: Thomas B. Shope, Center for Devices

and Radiological Health (HFZ-140), Food and Drug Administration, 5600

Fishers Lane, Rockville, MD 20857, 301-443-3314, ext. 32.

SUPPLEMENTARY INFORMATION:

I. Background

FDA, under authority conferred by the Public Health Service Act as

amended by the Radiation Control for Health and Safety Act (RCHSA) of

1968 (Pub. L. 90-602 (21 U.S.C. 360hh-360ss)), administers an

electronic product radiation control program to protect the public

health and safety. This authority provides for the development and

administration of radiation safety performance standards for electronic

products.

In order for mandatory performance standards to achieve intended

public health protection, attention must be given to keeping the

requirements of standards updated and appropriate. A number of

technological developments have been or will be implemented for

radiographic and fluoroscopic x-ray systems that are not addressed by

the performance standard or that present problems in the application of

the requirements of the current standard. FDA is developing proposed

amendments to the performance standard for radiographic and

fluoroscopic systems that take into account new technology, clarify

certain provisions, and address additional requirements that may be

determined to be necessary to provide for adequate radiation safety of

these systems.

On October 16 and 17, 1992, the American College of Radiology and

FDA sponsored a workshop on fluoroscopy to develop strategies for

improvement in performance, safety and control of fluoroscopic

equipment. Physicians, physicists, State and Federal government

regulators, and fluoroscopic equipment manufacturers attended the

workshop. They discussed and made recommendations for different ways to

approach fluoroscopic radiation safety issues and concerns, including

regulatory solutions.

In the Federal Register of May 19, 1994 (59 FR 26402), FDA

published a final rule effective May 19, 1995, amending performance

requirements for fluoroscopic systems to address the immediate concern

of preventing unlimited exposure rates during the high-level control

mode of fluoroscopic system operation. The TEPRSSC discussed the status

of standards for fluoroscopic systems and new clinical uses during a

meeting held on April 9 through 10, 1996. TEPRSSC is a permanent

statutory advisory committee established by statute that FDA must

consult prior to issuing standards under the RCHSA.

At a meeting of the TEPRSSC held on April 8 through 9, 1997, FDA

presented general concepts for amendments to the performance standard

for radiographic and fluoroscopic systems.

The committee recommended that FDA pursue development of the

amendments in the areas discussed in section II of this notice.

A transcript of the TEPRSSC April 8 through 9, 1997, meeting may be

ordered from Miller Reporting Co., Inc., 507 C St. NE., Washington, DC

20002, 202-546-6666 or FAX 202-546-1502.

Individuals or organizations wishing to receive copies of draft

amendments or related documents distributed for review during the

development of these amendments may have their names placed on the

mailing list by writing to: Office of Science and Technology (HFZ-140),

Center for Devices and Radiological Health, Food and Drug

Administration, 5600 Fishers Lane, Rockville, MD 20857, FAX 301-443-

9101, e-mail: [email protected]

II. Concepts for Amendments to the Standard

FDA has identified the following nine areas as candidates for

amendments to accommodate changes in technology and clinical use of

radiographic and fluoroscopic systems. The discussion below each

concept is not intended to indicate the specific content of the

proposed amendment to be developed, but is meant only to describe the

need and FDA's proposed approach. The specific regulatory changes or

proposed standards will be included in a future proposed rule. Comments

received in response to this notice will be used to develop the

proposed amendments. FDA requests comments on the following conceptual

changes:

1. Conversion to the International System of Units (SI) quantities

and units for the entire standard. This proposal is to amend all

sections of the performance standard for diagnostic x-ray systems to

use the radiation quantity ``air kerma'' in place of the quantity

``exposure'' and to change the units to the SI.

2. Clarification of applicability of requirements to technological

developments, such as digital imaging, digital recording and solid-

state x-ray imagers. The current organization and structure of the

standard assumes the presence of an x-ray image intensifier as the

basis for many of the requirements for fluoroscopic systems. This

assumption may be inappropriate for digital fluoroscopy systems that

may use new types of digital image receptors. Such systems may not have

an image intensifier tube. The structure of the radiographic section of

the standard is based on radiographic film as the image receptor and

revisions are needed to incorporate technological developments in that

area. It would be desirable to the extent possible to use terminology

consistent with usage adopted by the International Electrotechnical

Commission (IEC).

3. Amendment to incorporate draft Compliance Policy Guide on

Information to be Provided to Users (21 CFR 1020.30(h)). This proposal

would amend the requirements on the content of information that must be

provided to users to include specific information on the air kerma rate

for certain fluoroscopic modes of operation. This amendment would

incorporate into the standard a draft Compliance Policy Guide that has

been developed, but not yet issued, and is intended to interpret

Sec. 1020.30(h) for certain ``unique'' modes of fluoroscopic system

operation.

4. Amendment to add requirements for minimum half-value layer (HVL)

for systems designed for interventional radiology (Sec. 1020.30(m)).

This proposal would increase the minimum half-value layer requirements

for fluoroscopic systems designed for interventional radiology. Such a

requirement will require definition of a ``fluoroscopic system designed

for interventional

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fluoroscopy.'' As a concept for discussion, fluoroscopic systems

designed for interventional radiology might be defined as systems that

permit the beam axis to be positioned at an angle relative to the

normal to the table top. Systems in which the x-ray beam direction is

fixed with respect to the plane of the tabletop, such as conventional

radiographic/ fluoroscopic systems, would not be included in this

definition.

5. Amendment to require improved x-ray field limitation (21 CFR

1020.32(b)(2)(v)). This proposal would require improved limitation of

the x-ray field for fluoroscopic equipment to match the actual area of

the image receptor being used for image capture, thereby reducing the

amount of non-useful beam striking the patient.

6. Amendment to clarify the requirements for the minimum source-

skin distance for small, mobile, or portable mini C-arm systems

(Sec. 1020.32(g)). This amendment would address numerous requested and

granted variances for fluoroscopic systems that have limited source-

image receptor distances. The amendment would specify the conditions

under which a shorter-than-standard source-skin distance is permitted

and would obviate the need for continued variances from the standard.

7. Amendment to require indication of cumulative exposure time on

fluoroscopic systems (Sec. 1020.32(h)). The proposed amendment would

require the means to indicate the cumulative time of fluoroscopic

irradiation of a patient during an examination or procedure.

8. Amendment to require provision of ``last-image-hold'' feature on

fluoroscopic systems (Sec. 1020.32(j)). This amendment would require

that all fluoroscopic x-ray systems be provided with a means to

continuously display the last image acquired following termination of

any exposure period.

9. Amendment to require indication of air kerma rate and cumulative

air kerma on fluoroscopic systems (Sec. 1020.32(k)). The proposed

amendment would require the means to display to the fluoroscopist at

the fluoroscopist's working position the cumulative air kerma and the

air kerma rate (air kerma per unit time) at which air kerma accrues

during irradiation of a patient in an examination or procedure.

III. Electronic Access

The summary of concepts for amendments entitled ``Concepts for

Proposed Amendments to the Performance Standard for Diagnostic X-ray

Systems, August 1, 1997,'' may be accessed at the CDRH Home Page on the

World Wide Web. It is available on the Topic Index page at: http://

www.fda.gov/cdrh/topindx under ``Fluoroscopy''. A text-only version of

the CDRH site is also available from a computer or VT-100 compatible

terminal by dialing 800-222-0185 (terminal settings are 8/1/N). Once

the modem answers, press Enter several times and then select menu

choice 1: FDA BULLETIN BOARD SERVICE. From there, follow instructions

for logging in, and at the BBS TOPICS PAGE, arrow down to the FDA Home

Page (do not select the first CDRH entry). Then select Medical Devices

and Radiological Health. From there, select CENTER FOR DEVICES AND

RADIOLOGICAL HEALTH for general information, or arrow down for specific

topics.

The document may also be obtained by fax by calling the CDRH Facts-

On-Demand (FOD) system at 800-899-0381 or 301-827-0111 from a touch-

tone telephone. At the first voice prompt press 1 to access DSMA Facts,

at the second voice prompt press 2, and then enter the document number

591 followed by the pound sign (#). Then follow the remaining voice

prompts to complete your request.

A summary of the TEPRSSC April 8 through 9, 1997, meeting is

available on the CDRH Home Page at the same address given above for the

concepts for amendments document.

IV. Comments

Interested persons may, on or before March 11, 1998, submit to the

Dockets Management Branch (address above) written comments regarding

this proposed amendment. Two copies of any comments are to be

submitted, except that individuals may submit one copy. Comments are to

be identified with the docket number found in brackets in the heading

of this document. Received comments may be seen in the Dockets

Management Branch between 9 a.m. and 4 p.m., Monday through Friday.

Interested persons also are invited to participate in the

development of proposed amendments by submitting written data, views,

or arguments concerning the subject matter of the amendments, or

related topics suggested for inclusion in the amendments. In addition

to general comments and recommendations, respondents are encouraged to

include suggested text for provisions of the proposed amendments that

reflect their recommended performance requirements. A statement of

rationale should accompany any such proposed text. When a determination

is made on the content of the proposed amendments, they will be

published as notices of proposed rulemaking with opportunity given for

public comment. Information and comments are specifically invited on

the following topics:

1. For concepts 4 through 9 in section II of this document,

recommendation for whether the amendments should be limited only to

equipment designed for interventional procedures or for all

fluoroscopic systems. If only for interventional systems, how should

``interventional fluoroscopic systems'' be defined?

2. The desirability and technical feasibility of amendments of the

type described in section II of this document.

3. Recommended performance requirements to be included in the

proposed amendments, including attendant methods and conditions of

measurement.

4. Suggestions and supporting data for other amendments to the

performance standard for radiographic or fluoroscopic equipment,

including moving towards more outcome-based performance standards,

which may be needed to provide for adequate radiation safety.

5. The possible environmental impact of this action, including

factors such as radiation exposure reduction or prevention and economic

consequences in relation to expected benefits (cost-benefit

relationship), and the anticipated costs of providing such features or

meeting the requirements.

6. Any additional terms or definitions that are needed to better

specify the intent or meaning of the regulations as they apply to the

equipment.

This ANPRM is issued under 21 U.S.C. 321 and under the authority of

the Commissioner of Food and Drugs.

Dated: October 29, 1997.

William K. Hubbard,

Associate Commissioner for Policy Coordination.

[FR Doc. 97-32462 Filed 12-10-97; 8:45 am]

BILLING CODE 4160-01-F