[Federal Register Volume 61, Number 65 (Wednesday, April 3, 1996)]
[Proposed Rules]
[Pages 14908-14920]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-7833]
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DEPARTMENT OF HEALTH AND HUMAN SERVICES
DEPARTMENT OF HEALTH AND HUMAN SERVICES
Food and Drug Administration
21 CFR Part 900
[Docket No. 95N-0195]
RIN 0910-AA24
Proposed Quality Standards for Mammography Equipment and Quality
Assurance
AGENCY: Food and Drug Administration, HHS.
ACTION: Proposed rule.
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[[Page 14909]]
SUMMARY: The Food and Drug Administration (FDA) is proposing to amend
the regulations for facility standards established in the interim
regulations implementing the Mammography Quality Standards Act of 1992
(the MQSA). This proposed rule will establish additional performance
standards for mammography equipment and equipment-related quality
assurance practices currently required of mammography facilities. FDA
is proposing these amendments based on advice from the National
Mammography Quality Assurance Advisory Committee (NMQAAC), mammography
equipment manufacturers, and public comments received in response to
the interim regulations. This proposed rule is intended to assure safe,
accurate, and reliable mammography on a nationwide basis. This document
is the fifth of five related proposed rules that FDA is publishing
concurrently in this issue of the Federal Register.
DATES: Written comments by July 2, 1996. The agency is proposing that
any final rule based on this proposed rule become effective 1 year
after its date of publication in the Federal Register, except where
otherwise indicated.
ADDRESSES: Submit written comments to the Dockets Management Branch
(HFA-305), Food and Drug Administration, rm. 1-23, 12420 Parklawn Dr.,
Rockville, MD 20857. The Regulatory Impact Study (RIS) is available at
the Dockets Management Branch for review between 9 a.m. and 4 p.m.,
Monday through Friday. Requests for copies of the RIS should be
submitted to the Freedom of Information Staff (HFI-35), Food and Drug
Administration, 5600 Fishers Lane, rm. 12A-16, Rockville, MD 20857.
FOR FURTHER INFORMATION CONTACT: Charles K. Showalter, Center for
Devices and Radiological Health (HFZ-240), Food and Drug
Administration, 1350 Piccard Dr., Rockville, MD 20850, 301-594-3332.
SUPPLEMENTARY INFORMATION:
I. Background
This proposal is the fifth of five related proposed rules published
in this issue of the Federal Register to amend interim regulations
published on December 21, 1993 (58 FR 67558 and 58 FR 67565),
implementing the MQSA (Pub. L. 102-539). The first proposed rule,
``Quality Mammography Standards; General Preamble and Proposed
Alternative Approaches'' contains background information and a summary
of the preliminary analysis of the costs and benefits of the proposed
rules, a description of the information collection requirements,
proposed revisions to Sec. 900.1 Scope and Sec. 900.2 Definitions (21
CFR 900.1 and 900.2), and proposed alternative approaches to
mammography quality standards and a request for comments on the
proposed alternatives.
II. Provisions of the Proposed Rule
A. Development of the Proposed Regulation
As with the interim regulations, FDA was guided in the development
of this proposed rule by the intent of the legislation to guarantee
access to safe and effective mammography services for all women in the
United States (Ref. 1). FDA also relied upon three major sources of
information, in addition to the expertise and research of FDA
personnel.
First, the agency considered public comments received on the
interim regulations. The agency received 103 comments from individuals
and organizations, including: Professional organizations, medical
facilities, State agencies, consumer groups, manufacturers, and
individual physicians, medical physicists, and radiologic
technologists. The proposed regulations were also discussed in a series
of quarterly meetings with the NMQAAC. Members of the NMQAAC include
interpreting physicians, medical physicists, radiologic technologists,
representatives of State agencies, and consumer representatives.
Consultants to the NMQAAC and guests invited to attend the committee
meetings in recognition of their expertise in mammography also
participated in these discussions of the proposed regulations. Finally,
the agency obtained input through discussions with various professional
and trade organizations and individuals with expertise related to
mammography equipment, quality assurance, and infection control.
Preliminary drafts of the proposed regulations were made generally
available at the NMQAAC meetings and through notices of availability
published in the Federal Register on December 30, 1994 (59 FR 67710)
and January 26, 1995 (60 FR 5152).
Organizations participating in discussions of the regulations
included the National Electrical Manufacturers Association (NEMA), the
Conference of Radiation Control Program Directors (CRCPD), and four
national medical physicist organizations: The American Association of
Physicists in Medicine, the American Academy of Health Physics, the
American College of Medical Physicists, and the Health Physics Society.
A discussion of the proposed amendments and a summary and analysis
of NMQAAC input and public comments regarding the regulations is
provided below.
B. Equipment Regulations
In Sec. 900.12(b) of the interim regulations, performance standards
were established for equipment used in the production of mammograms.
These standards were substantially harmonized with existing standards,
such as those established by the Health Care Financing Administration
(HCFA), the American College of Radiology (ACR), and some States. This
interim approach was consistent with the legislative intent of the MQSA
(Ref. 1) and enabled FDA to certify the thousands of facilities that
already met voluntary accreditation standards prior to publication of
the interim regulations. This approach also allowed the agency to
concentrate its initial resources on facilities with no such prior
accreditation. Now that additional input regarding the equipment
standards has been obtained from the NMQAAC, equipment manufacturers,
and the public, FDA is proposing additional requirements in
Sec. 900.12(b) for radiographic, processing, and ancillary equipment
used in mammography.
In developing the proposed equipment standards, FDA recognized the
need to balance the economic impact of new standards against the
associated gains to the public health. It was also necessary for FDA to
consider the availability (initially, and over time) of mammography
equipment meeting the new requirements. This was necessary because, for
some requirements, considerable time might be needed to allow for
redesign, production, purchase, and installation of new equipment, or
for retrofitting of the installed equipment base. The amount of time
needed would depend on the nature of the requirement, the capacity of
manufacturers, and the number of facilities already meeting the
requirement. In consideration of these factors, the agency is proposing
to phase in the equipment standards in proposed Sec. 900.12(b) over the
next 1 to 10 years.
In accordance with guidance from the NMQAAC, three effective dates
are being proposed for different phases of implementation. Requirements
to be implemented during the first phase would have an effective date
of 1 year after the date of publication of the final rule. Such
requirements would cover aspects of equipment performance that the
NMQAAC considered fundamental to the delivery of quality mammography.
Requirements to be
[[Page 14910]]
implemented during the second and third phases would have effective
dates of 5 and 10 years after the date of publication of the final
rule, which FDA estimates would correspond to approximately October 1,
2000, and October 1, 2005, respectively. Although these dates have been
used for the purpose of this proposal, the final effective dates will
be modified to correspond to the dates 5 and 10 years after the
publication date of the final rule. The agency believes that this
advance guidance to the industry regarding upcoming changes in
requirements and the phasing in of such requirements will minimize the
economic impact of implementing improvements in mammography.
Several comments received on the interim regulations indicated a
lack of awareness of agency plans for notice-and-comment rulemaking in
promulgating final regulations, or listed specific recommendations for
changes or additions. Most of the recommendations for specific
equipment requirements have been incorporated into the proposed
standards. A summary of these comments and the FDA responses follow:
1. General
One comment disagreed with the prohibition in the interim
regulations against performance of mammography using a conventional x-
ray system with device modifications or options specifically designed
to enable use of the system for mammography. The comment stated that
allowing use of such systems for mammography would represent an
economical source of equipment that should not be problematic as long
as the systems can produce quality images without compromising examinee
safety or dosage considerations.
In response to this comment, FDA notes that the MQSA expressly
states that equipment standards must ``require use of radiological
equipment specifically designed for mammography'' (42 U.S.C.
263b(f)(1)(B)). Therefore, FDA is continuing the prohibition against
use of nonmammography x-ray equipment for the production of mammograms.
One comment supported the interim requirements in Sec. 900.12
(b)(2)(i) to (b)(2)(iii) but requested the addition of two subsections
requiring: (1) Cassettes of appropriate size, to allow the technologist
to obtain a complete breast image on a single film, and (2) grids
specifically designed for mammography for each size of cassette.
FDA agrees with these comments and has included such requirements
in proposed Sec. 900.12(b)(4).
Three comments suggested that the provision in
Sec. 900.12(b)(2)(iii), requiring mammography equipment to have a
removable grid, be expanded to require a reciprocating removable grid.
A reciprocating (moving) grid would avoid grid lines often seen with a
stationary grid. One comment did not understand the requirement in
Sec. 900.12(b)(2)(iv), and in particular the phrase ``removable grid.''
The comment stated that, if the intent is not to reduce radiation dose,
the appropriate word would be ``moving,'' rather than ``removable,''
because moving the grid improves image quality. Also, the comment
questioned whether this standard refers to regular view or
magnification mode.
FDA believes that all equipment should be provided with
reciprocating (moving) grids and that these grids should be removable
for all systems providing magnification capability. These grid
requirements have been proposed in Sec. 900.12 (b)(4)(ii) and
(b)(4)(iii). The intent is that the grid be removable so that
magnification procedures can be completed properly without increasing
the radiation dose to the examinee.
Discussions with the NMQAAC indicated considerable concern that
radiographic equipment be equipped to enable a number of routine views
for all examinees. Of specific concern were the mediolateral oblique,
caudo-cranial, and cranio-caudal views, and the need to ensure that
each facility has equipment that allows for variation in individual
body habitus.
Under Sec. 900.12(b)(3) (ii) and (iii), FDA has proposed specific
requirements related to the motion capability of the gantry assembly
that the NMQAAC believes will achieve this goal.
The NMQAAC also strongly recommended that all mammography systems
be required to have a light field that approximates the x-ray field and
passes through the collimation system. This configuration would assist
in positioning and allow visual verification that the radiographic view
of the breast remains unobstructed. In response to this NMQAAC
recommendation, FDA received comments from a major trade association
representing manufacturers of mammography x-ray equipment indicating
that a significant portion of the installed equipment base would not
meet these requirements. This association further indicated that there
may be significant costs associated with retrofitting existing
equipment to comply with this recommendation.
FDA is proposing to require in Sec. 900.12(b)(5) that all
mammography systems have the light field recommended by the NMQAAC,
effective October 1, 2000. FDA is requesting public comment on this
proposed requirement and its likely impact on the cost and availability
of mammography services.
Proposed Sec. 900.12(b)(11)(i) references the requirements in
Sec. 1020.30(m)(l) (21 CFR 1020.30(m)(1)) for minimum beam quality
(half-value layer (HVL)) for mammography x-ray systems. FDA realizes
that this reference is redundant with proposed Sec. 900.12(b)(2), but
believes that it is necessary to clarify the requirements stated in
proposed Sec. 900.12(b)(11)(i).
One comment stated that, in addition to requiring the incorporation
of a breast compression device, the regulation should mandate use of
this device (at least for screening mammography), because compression
enables better visualization of the breast and permits lower radiation
dose to be used.
FDA recognizes that use of a breast compression device is
considered by professionals to be essential for proper imaging of the
breast. By requiring that each system be equipped with a breast
compression device, FDA has attempted to ensure that this feature is
always available to the technologist. However, because the requirement
that the compression device always be used would be extremely difficult
to enforce, such a requirement has not been proposed.
In Sec. 900.12(b)(12), FDA is proposing that all mammography
systems be equipped with both foot-controlled power driven and fine
adjustment controls (either manual or power driven). The intent of this
requirement is to allow the technologist to use both hands to position
the examinee under foot regulated power control, and to make final
adjustments to the compression under the increased control provided by
the fine adjustment mechanism. FDA is specifically requesting
additional comments on this proposed requirement. For example, would a
power-only system that provided a slower, more controlled, final
application of power driven compression be as useful as a combination
of power and manual compression?
One comment suggested requiring that all compression equipment
allow for automatic release of compression in case of power or
mechanical failure.
FDA recognizes that some facilities consider an automatic
compression release desirable, and the proposed regulations permit
this. However, under
[[Page 14911]]
some conditions, an automatic release may represent a physical hazard
to the examinee. Therefore, under Sec. 900.12(b)(12)(ii), FDA is
proposing certain restrictions on systems that provide an automatic
decompression feature.
Two comments noted that the interim regulations do not require that
the breast compression device be parallel to the imaging plane, thus
potentially allowing unequal compression to occur.
FDA agrees and the proposed regulations contain a requirement under
Sec. 900.12(b)(12)(iii)(B) to address this concern. FDA notes, however,
that there is one manufacturer that does not meet this proposed
requirement because it claims that the nonparallel design of its device
provides uniform compression. FDA requests comments (and supporting
data) regarding whether the agency should: (1) Modify the proposed
regulations to accommodate this alternative design, or (2) retain the
requirement as proposed and allow manufacturers to obtain variances to
market alternative devices, in accordance with the alternative
equipment provision in proposed Sec. 900.18 (published elsewhere in
this issue of the Federal Register).
Seven comments recommended that FDA require automatic exposure
control (AEC) capability on all systems. One comment suggested that the
equipment requirements should be more specific to address phototimers,
acceptable operating energies, radiation output, and milliampere (mA)
requirements.
FDA agrees and has included requirements for each of these areas in
proposed Sec. 900.12 (b)(13), (b)(14), and (b)(15). These requirements
were supported by the NMQAAC.
One comment suggested that all mammography systems installed or
transferred following implementation of the interim regulations should
provide for milliampere second (mAs) readout following each exposure.
FDA agrees that mAs readout is important and under proposed
Sec. 900.12(b)(13)(iv), all equipment that automatically selects the
mAs will be required to indicate the mAs value used following the
exposure.
Two comments suggested a number of technical requirements that all
mammography equipment should be required to meet.
The recommended requirements are supported by FDA and the NMQAAC
and have been included in proposed Sec. 900.12 (b)(4), (b)(5), (b)(8),
(b)(11), (b)(14), and (b)(15), or were already covered under the
diagnostic x-ray system performance standard in Secs. 1020.30 and
1020.31 (21 CFR 1020.31), with the exception of the following:
(1) One comment suggested that a tungsten target tube should never
be used for screen-film mammography.
FDA disagrees with this comment. The agency believes there is no
evidence to support prohibiting the use of tungsten target tubes and
has not included this limitation in the proposed regulations.
(2) One comment stated that the nominal focal spot size should be
regulated in conjunction with the system source-image receptor distance
(SID).
FDA is proposing to address the issue of focal spot size through
the proposed requirement for system resolution in Sec. 900.12(b)(8).
The intent of this requirement (which has been adopted by the ACR), is
to provide a test for system resolution that is easier to perform than
a focal spot size determination.
(3) One comment stated that the SID should not be less than 50
centimeters (cm).
FDA is proposing to adopt the ACR's minimum requirement for SID,
which is 55 cm.
2. Xeromammography
Three comments requested FDA to prohibit use of xeromammography,
which the comments believed produces lower quality mammograms at a
higher dose of radiation than screen-film modalities.
FDA is aware of the controversy regarding use of xeromammography,
but the agency believes that, with respect to certain diagnostic
applications, the modality may still be equal to screen-film systems.
At the same time, the virtual disappearance of xeromammography units
from the marketplace indicates that the mammography community itself is
discontinuing the general use of this modality. Both the interim and
proposed regulations place a maximum limit on the dose that can be
delivered to an examinee using xeromammography. In proposed
Sec. 900.12(c), published elsewhere in this issue of the Federal
Register, the dose that may be delivered by xeromammography has been
reduced from the interim requirement of 4.0 milliGray (mGy) to 3.0 mGy.
This decision was based on communication from the manufacturer of
xeromammography systems informing FDA that properly adjusted and
maintained xeromammography systems could meet such a requirement. Under
the proposed regulations, therefore, the dose limits for screen-film
and xeromammography would be the same.
One comment questioned whether xeromammography will continue to be
considered inadequate for screening purposes, in accordance with HCFA
regulations.
FDA regulations replace those issued by HCFA concerning mammography
facilities and FDA regulations do not prohibit the use of
xeromammography for screening.
3. Operator Protection
Two comments expressed concern that no regulations addressed the
protection of the operator by requiring radiation protective barriers
or anchored exposure switches.
FDA believes that specific operator safety requirements remain the
responsibility of State and local authorities regulating the use of
diagnostic x-ray equipment. Therefore, FDA has not proposed any
requirements relating to this aspect of the facility operation.
4. Examinees With Disabilities
In addition to meeting the specific requirements listed in this
regulation, it was the opinion of the NMQAAC that each facility has the
responsibility to accommodate examinees with physical disabilities and
to provide such examinees with access to the same quality mammography
provided to other examinees. The NMQAAC further believed that
facilities that could not provide such special services should be
required to screen prospective examinees during the appointment
scheduling process and refrain from scheduling disabled examinees who
cannot be accommodated.
FDA has included a requirement in proposed Sec. 900.12(b)(16)
reflecting this recommendation. The agency also encourages facilities
that cannot accommodate disabled individuals to refer these individuals
to a facility that is equipped to provide mammography services for
them. FDA encourages comments regarding the necessity and
appropriateness of this section in light of the requirements currently
imposed by the Americans with Disabilities Act of 1990.
5. Interventional Mammography
Five comments indicated that standards and test methods are needed
for stereotactic units and dedicated biopsy-type machines.
FDA agrees with these comments. However, the agency believes that
no consensus exists in the mammography community regarding appropriate
standards for such equipment and
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procedures. Various public and private organizations are working to
develop such standards and FDA will propose requirements some time in
the future.
6. International Harmonization
In the Federal Register of November 28, 1994 (59 FR 60870), FDA
published an agency policy on international harmonization of regulatory
requirements. In accordance with that policy, the agency requests
comments regarding the implications of the proposed equipment standards
on any related international harmonization efforts for mammography
equipment.
C. Quality Assurance (QA)--Equipment
The primary purpose of the equipment aspects of the quality
assurance program is to prevent problems with equipment or detect and
correct problems before they can have a significant effect on clinical
image quality. To achieve this, the performance parameters of the
equipment must be tested at appropriate frequencies, the test results
must be promptly analyzed to determine if the performance of the
equipment is satisfactory, and any identified problems must be
corrected as soon as possible. In addition, followup tests must be
conducted to determine whether the corrective actions were effective.
Requirements for these types of tests are proposed in Sec. 900.12(e).
1. Testing of Screen-Film Systems
Proposed Sec. 900.12 (e)(1) through (e)(5) establish the minimum
performance tests to be conducted on screen-film systems. The agency
has decided not to propose extensive detailed requirements in order to
provide facilities with the flexibility to use alternative methods that
might be equally satisfactory or to add other tests. Under the interim
regulations, FDA adopted the ACR's relatively detailed QA requirements
(Ref. 2). However, the NMQAAC has advised FDA that these ACR
requirements were intended to be used as guidelines, not in a
prescriptive manner.
Therefore, the agency is proposing to limit the quality assurance
requirements for equipment to a more general listing of the required
tests, establishment of the required test frequencies, definition of
action limits, and, in some cases, specification of critical test
conditions.
At the July 1994 NMQAAC meeting, an additional daily total system
test was discussed, which read as follows:
Total System Test:
(A) The optical density (OD) of the film at the center of an image
of a uniform phantom when exposed in AEC mode shall not change by more
than 0.20 from the established operating level. The OD of
the established operating level shall be above 1.20. The mAs shall not
change by more than 10 percent from the established value corresponding
to the operating level OD.
(B) The film shall be examined for system artifacts.
The agency believes that this total system test, in conjunction
with the processor performance test set forth in proposed
Sec. 900.12(e)(1), should be performed daily before the first examinee
is examined. The performance of these two tests will assure the overall
quality of the x-ray machine, processor, and films. The records of the
tests will also enable a medical physicist to quickly detect the source
of a problem when it occurs. The above described system test takes only
a few minutes to perform and can be performed by a quality control
technologist.
The NMQAAC suggested that more data about the usefulness of the
total system test should be gathered before this test is introduced as
a required daily test. The NMQAAC also agreed that the image quality
evaluations described in proposed Sec. 900.12(e)(2) should be performed
weekly if the total system test is not required.
The agency is proposing system testing requirements in accordance
with the NMQAAC's advice. Although FDA is not proposing to require the
daily total system test at this time, the agency requests comments
regarding the utility of this test. If the total system test were
introduced, FDA would revise the regulations to require monthly, rather
than weekly, performance of the image quality evaluations in proposed
Sec. 900.12(e)(2).
Several comments on the interim regulations raised concern about
basing the quality control requirements on a single manual, such as the
ACR manual (Refs. 2 and 3).
In the proposed regulations, no manual has been referenced. A
facility may consult any appropriate manual or rely on agency guidance
to meet the requirements in proposed Sec. 900.12(e)(1) through (e)(5).
One comment requested that any standard that is developed be
achievable with current technology. As an example of a test that the
comment believed could not be achieved using current technology, the
comment cited ACR's criteria for passing the screen-film contact test,
as described in the 1992 ACR manual (Ref. 2).
The agency is convinced, based on the expertise of its staff and
experience with the interim regulations, that the requirements and
action limits proposed in this regulation can be met with current
technology.
One comment suggested that a minimum allowable dose should be
specified for a 4.5-cm compressed breast composed of 50 percent
glandular tissue and 50 percent adipose tissue. Also, one comment
suggested that the mean glandular dose should not exceed 1.0 mGy for
screen-film systems without grids.
FDA believes that placing a lower limit on dose may hamper further
technological advancement of systems that may reduce the dose without
compromising image quality. In addition, the agency has decided to use
only one upper dose limit for all systems.
Several comments stated that FDA's data indicate that an accepted
phantom simulates a 4.2-cm thick compressed breast, not 4.5 cm.
Therefore, the regulations should use a 4.2-cm thickness. One comment
stated that the dose should be determined using clinically employed
technique factors for a 4.5-cm thick compressed breast composed of 50
percent glandular tissue and 50 percent adipose tissue, instead of
using the phantom technique factors promulgated in the interim
regulations. Two comments noted that, in many cases, the technique
factors used by a facility to produce phantom images do not reflect the
technique factors actually used on examinees. This could result in
examinees receiving doses exceeding the limits specified in the
regulations, even though the facility technically passed the compliance
test by using their phantom image technique factors. One comment stated
that the dose should be determined under the facility's proposed
technique factors for a 4.2-cm thick compressed 50 percent glandular/50
percent adipose breast.
After review of these comments, FDA is proposing to require
clinical technique factors and a phantom simulating a 4.2-cm thick
compressed 50 per cent glandular/50 per cent adipose tissue breast to
be used during dose measurements. Although FDA has data to show that an
accepted phantom simulates the attenuation properties of 4.2 cm of 50/
50 compressed breast tissue, the agency recently has developed
additional data indicating that the phantom may be equivalent in
attenuation properties to approximately 4.0-cm of 50/50 compressed
breast tissue, as per the dose model used to convert skin exposure to
dose. The agency, therefore, is soliciting more information and
comments on the appropriate equivalent thickness of the phantom for
dose calculation.
[[Page 14913]]
One comment requested an explanation of the methods for obtaining
FDA certification of QA phantoms. Another comment suggested that the
regulations should specify one, and only one phantom, and should
specify the minimum acceptable performance, rather than leaving this to
the discretion of accreditation bodies.
The agency continues to believe that accreditation bodies should
establish phantom specifications and related performance criteria.
However, as part of it responsibilities for accreditation body approval
and oversight, FDA will examine each body's phantom specifications and
performance requirements, which will have to be substantially the same
among different accreditation bodies.
One comment recommended that FDA publish some type of voluntary
form(s) for maintaining appropriate records.
FDA believes it is inadvisable for the agency to generate sample
forms because such forms may be unnecessarily restrictive. Facilities
that do not want to generate their own forms may adopt forms that are
provided in various manuals, as appropriate.
2. Systems With Other Modalities
Proposed Sec. 900.12(e)(6) would require that the facility quality
assurance program for systems with image receptor modalities other than
screen-film (e.g., xeromammography) be substantially the same as that
recommended by the image receptor manufacturer. This section would also
require that such systems meet the same dose limits as screen-film
systems.
3. Mobile Units
Proposed Sec. 900.12(e)(7) would establish additional quality
assurance requirements for mobile mammography units. These mobile units
are operated in a variety of environments and undergo the stress of
frequent movements, often over rough surfaces. In view of this, a
number of comments on the interim regulations urged FDA to require that
a phantom image quality test be performed after every move, before any
additional examinations are conducted at the new site. These comments
stated that if a problem occurs after a move which could compromise the
quality of clinical images, this problem should be detected and
corrected before any further clinical use of the equipment. These
comments believe this additional testing is necessary for mobile units
in order to minimize the need for repeat examinations, which would
result in additional radiation exposure and expense and might result in
some cancers going undetected if it is not possible to get examinees to
return to the facility.
In contrast, other comments noted that a requirement for a post-
move, pre-examination image quality test would pose great difficulties
to mobile services that are some distance from their home base and do
not have access to adequate processing at the test site. These comments
expressed concern that such a requirement would cause some mobile
services to cease operation and would significantly reduce access to
mammography in rural and inner city areas. Several comments cited their
own experience in stating that image quality tests conducted after
moves rarely or never show that a problem has occurred because of the
move. The preliminary results of a survey of mobile facilities
conducted by the ACR found that nearly 90 percent of the facilities
rarely found problems after a move. However, the remaining facilities
found problems as often as daily or weekly.
The 1992 edition of the ACR QA manual (Ref. 2) recommended that an
image quality test be conducted after every move, but was somewhat
ambiguous regarding when the processing and analysis of the images
should occur. However, the agency has been informed by members of the
ACR committee who were responsible for the manual that they did not
intend to require processing before further examinations were
conducted. The 1994 edition of the ACR QA manual (Ref. 3) completely
dropped the requirement for conducting image quality testing after
every move. Under this revised ACR requirement, therefore, mobile units
are required to undergo image quality testing at the same frequency as
fixed units, which ordinarily is monthly.
At its September 1994 meeting, the NMQAAC discussed this issue and
recommended that post-move, pre-examination testing of mobile units be
required in the final regulations. FDA agreed with this recommendation
and has incorporated it in proposed Sec. 900.12(e)(7).
The NMQAAC further recommended allowing use of a method of testing
based on post-exposure mAs readout values in place of phantom image
testing. FDA has decided not to require a particular method of testing
at this time. Instead, the agency is proposing to require each facility
to adopt a test method that will verify the adequacy of image quality
following a move, but to leave the choice of test method to the
facility. The agency believes that this approach will give individual
facilities maximum flexibility. FDA will issue guidance documents that
reflect the agency's current thinking about test methods that are
appropriate. At this time, FDA expects those methods to include the
method recommended by the NMQAAC as well as the traditional phantom
image quality test.
Including these methods of testing in guidance rather than in
regulations has the advantage of increased speed and flexibility. As
the agency becomes aware of new test methods of proven value, the
agency's evaluation of such methods can be publicized through
modification of guidance materials much more rapidly than through
amendment of regulations. In addition, mobile units will have the
option of using post-move pre- examination image quality test methods
that are different from those described in guidance. Testing methods
described in these materials will guide inspectors as they evaluate the
adequacy of an individual facility's testing methods. Although the
methods described in guidance will represent the agency's most current
thinking about appropriate testing for this purpose, such guidance will
not bind the facility or the agency. If a facility chooses alternative
procedures, FDA encourages the facility to discuss the choice in
advance in order to prevent expenditure of efforts and resources on
testing that may later be determined to be unacceptable because it does
not establish the adequacy of image quality following a move.
4. Use of Test Results
Proposed Sec. 900.12(e)(8) describes how results from the tests
specified in paragraphs (e)(1) through (e)(7) would be used to ensure
that problems are detected and corrected before they adversely affect
the quality of examinations.
5. Survey
Proposed Sec. 900.12(e)(9) describes the activities that would have
to be carried out by the medical physicist as part of the annual
evaluation of facility equipment performance and quality assurance
programs. A concern raised at the February 1994 NMQAAC meeting and
elsewhere was that qualified medical physicists might delegate the
onsite survey work to less qualified personnel and merely review and
sign the survey report.
Because FDA is also concerned about such delegation occurring, the
agency is proposing in Sec. 900.12(e)(9)(i) that only qualified medical
physicists be authorized to conduct the surveys. The agency is further
proposing to require in Sec. 900.12(e)(9)(V) that the report be signed
and dated by the individual who
[[Page 14914]]
performs the survey. As is the case with the signature of the
interpreting physician on the mammography report (see discussion of
Sec. 900.12(c)(1) published elsewhere in this issue of the Federal
Register), the purpose of the signature requirement is to identify the
individual who performed or provided direct supervision of the work.
Therefore, in addition to handwritten signatures, FDA will accept
``signatures'' that are generated from computer systems, typewritten,
name stamped, and possibly provided in other ways. These requirements
would not prohibit physicists-in-training from performing surveys to
gain experience, but would require that such surveys be done under the
direct supervision of a fully qualified medical physicist, who would
have to sign the report as the responsible physicist. If another
individual performs any part or all of the survey under the direct
supervision of a medical physicist, that person and the part of the
survey that person performed must also be identified on the survey
report.
6. Mammography Equipment Evaluation
Proposed Sec. 900.12(e)(10) would require a mammography equipment
evaluation to be performed whenever a mammography unit or image
processor is installed or major components of that unit or processor
are changed. This requirement was added to ensure that the performance
of new or significantly changed equipment is evaluated, and problems
corrected, before such equipment is used during examinations. FDA
believes mammography equipment evaluation, rather than a complete
survey of the facility as described in Sec. 900.12(e)(9), is adequate
for this purpose because not all aspects of the facility operation
which are checked during a survey would be affected by the installation
of new equipment or the modification of old equipment.
The agency will describe its current thinking about appropriate
procedures for carrying out these evaluations in guidance documents and
will update that guidance, when warranted, to reflect scientific and
professional developments. Similarly, the agency will describe in
guidance its current thinking about appropriate qualifications for
persons doing this work. As discussed previously with respect to agency
guidance for testing mobile units, facilities will have the option of
using procedures other than those described in guidance or employing
individuals with qualifications different than those listed in
guidance, assuming such alternative procedures or qualifications are
adequate to examine equipment for such purposes. The guidance issued by
FDA will not be binding on either the facility or the agency. Once
again, however, FDA encourages facilities that choose alternative
personnel or procedures, to discuss the choice in advance in order to
prevent expenditure of efforts and resources on evaluations that may
later be determined to be inadequate.
FDA realizes that Sec. 900.12(e)(10), as presently proposed, raises
the question as to what constitutes a ``major component'' of the
equipment, i.e., what components would have a significant impact on the
performance of the equipment if their repair or replacement were done
improperly. The agency specifically requests comments on this issue.
7. Housekeeping and Maintenance Tasks
At its July 1994 meeting, the NMQAAC stressed the importance of
carrying out regular maintenance and housekeeping activities as well as
properly storing film and processing chemicals. However, the agency
decided, for two reasons, not to propose detailed and comprehensive
requirements for such activities.
First, failure to follow proper maintenance and housekeeping
activities at a facility will be revealed through failure of the tests
outlined in Sec. 900.12(e)(1) through (e)(6) and through adverse
findings in the physicist's survey. Additional detailed requirements
would be redundant.
Second, there are a wide variety of effective maintenance and
housekeeping activities. The agency believes that it would be overly
prescriptive to limit facilities to one set of activities in this area
by regulation.
At its January 1995 meeting, the NMQAAC agreed that the details of
these activities could be incorporated into guidance materials rather
than regulatory requirements. However, the members believed that
general requirements should be established for certain especially
important activities. Therefore, FDA is proposing to require in
Sec. 900.12(e)(11) that facilities establish and follow protocols for
the maintenance of darkroom, screen, and view box cleanliness.
8. Calibration of Exposure Measuring Instruments
In order to have reliable uniform dose measurements in facilities
all across the United States, it is important to have proper
traceability of the instruments used to measure x-ray exposure. The
agency is proposing to add in Sec. 900.12(e)(12) a requirement for
annual calibration of such instruments, which must be traceable to a
national standard.
9. Infection Control
Concern was expressed during the open public portion of several
NMQAAC meetings and by one comment on the interim regulations that,
because of the possibility of nipple discharge during mammography, FDA
should mandate the use of universal precautions during all mammography
examinations to protect examinees and health care workers from possible
transmission of bloodborne pathogens. The comment also expressed
concern that present procedures used to disinfect mammography equipment
between examinations are inadequate to prevent disease transmission.
FDA notes that the concept of ``universal precautions'' is an
approach to infection control stipulating that all human blood and
certain human body fluids should be treated as if known to be
infectious for human immunodeficiency virus (HIV), hepatitis B and C
viruses (HBV, HCV), and other bloodborne pathogens. The Occupational
Safety and Health Administration (OSHA) already mandates the use of
universal precautions for all situations where occupational exposure
can reasonably be anticipated (29 CFR 1910.1030). Although staff at the
Centers for Disease Control (CDC) have advised FDA that there have been
no reported cases of transmission of HIV, HBV, or HCV to examinees or
health care workers during mammography, such transmission is
theoretically possible (if no infection control precautions are taken).
Therefore, the OSHA regulations are applicable to the practice of
mammography, and it would be redundant for FDA to issue a universal
precautions requirement under the MQSA authority.
With respect to appropriate decontamination practices, members of
the NMQAAC noted during an advisory committee meeting that guidelines
and regulations addressing infection control practices relevant to
mammography are available from CDC (Ref. 4) and OSHA (29 CFR
1910.1030(d)(4)). These guidelines and regulations specifically address
the decontamination of medical equipment and working surfaces after
contact with blood or other potentially infectious materials. Local
infection control policies are also in effect in many locations.
In addition, the Association for the Advancement of Medical
Instrumentation (AAMI) recently published a technical information
report on reprocessing of reusable medical
[[Page 14915]]
devices (Ref. 5). Several other national and international standards
setting organizations are developing guidance in this area as well.
However, these guidelines, regulations, reports, and standards do not
completely cover all aspects of reprocessing mammography equipment,
because they may not address the special concerns of disinfecting
electrical equipment, and may not consider the effect of the
disinfecting agent upon the equipment. For these reasons, FDA is
developing a guidance document regarding labeling of reusable medical
devices for reprocessing in health care facilities (Ref. 6). A notice
of availability requesting comments on this guidance document was
published in the Federal Register on June 15, 1995 (60 FR 31484). FDA
and industry will utilize this document to ensure appropriate labeling
for new devices as well as for improving labeling for currently
marketed devices.
FDA believes that the concern raised by the comment transcends the
issue of reuse of mammography devices and addresses the broader general
issue of safe reuse of any reusable medical device. Therefore, it is an
issue to be resolved under the agency's general medical device
authority, rather than under the authority of the MQSA. In light of the
concerns raised, however, FDA is reviewing current guidance and
regulations, as well as additional guidance under development by the
agency, to determine whether new labeling information or accessories
are necessary with respect to reuse of mammography devices. FDA
encourages interested parties to communicate to the agency any concerns
and proposed solutions in this area.
To ensure that the practice of mammography benefits from infection
control guidance already available, FDA is proposing to require that
facilities establish, adhere to, and document their compliance with a
system of infection control. In addition to requiring compliance with
any applicable infection control regulations, each facility's system
would have to require adherence to infection control recommendations
provided by the manufacturer(s) of the mammography equipment used in
the facility, or, if adequate manufacturer's recommendations are not
available, adherence to generally accepted guidance on infection
control (e.g., Refs. 4 and 5), until such recommendations become
available.
III. Environmental Impact
The agency has determined under 21 CFR 25.24(e)(3) that this action
is of a type that does not individually or cumulatively have a
significant effect on the human environment. Therefore, neither an
environmental assessment nor an environmental impact statement is
required.
IV. Analysis of Impacts
FDA has examined together the impacts of this proposed rule and the
proposed rules on accreditation bodies, general facility requirements,
and personnel, published elsewhere in this issue of the Federal
Register, under Executive Order 12866, the Regulatory Flexibility Act
(Pub. L. 96-354), and under the Unfunded Mandates Reform Act. The
analysis has addressed the proposed requirements of these four rules as
one unit for purposes of determining their economic impact. The
preamble to the proposed rule ``Quality Mammography Standards; General
Preamble and Proposed Alternative Approaches,'' published elsewhere in
this issue of the Federal Register, contains a brief summary of the
cost and benefit determination and the Regulatory Impact Study that
details the agency's calculation of these economic impacts and is
available at the Dockets Management Branch (address above) for review.
FDA recognized that these proposed regulations may have a
disproportionate effect on small volume mammography facilities and is
currently collecting additional information on the potential impact on
this industry sector. The agency requests comments that will assist it
in accounting for this impact.
V. Paperwork Reduction Act of 1995
This proposed rule contains no information collection or
recordkeeping requirements under the Paperwork Reduction Act of 1995.
VI. Comments
Interested persons may, on or before July 2, 1996, submit to the
Dockets Management Branch (address above) written comments regarding
this proposal. 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 at the heading of this
document. Information submitted in response to this notice may be seen
in the office above between 9 a.m. and 4 p.m., Monday through Friday.
VII. References
The following information has been placed on display in the Dockets
Management Branch (address above) and may be seen by interested persons
between 9 a.m. and 4 p.m., Monday through Friday:
1. ``Report on the Mammography Quality Standards Act of 1992,''
U.S. Senate, Report 102-448, October 1, 1992.
2. American College of Radiology, ``Mammography Quality Control:
Radiologist's Manual, Radiologic Technologist's Manual, and Medical
Physicist's Manual,'' February, 1992.
3. American College of Radiology, ``Mammography Quality Control:
Radiologist's Manual, Radiologic Technologist's Manual, and Medical
Physicist's Manual,'' 1994.
4. Centers for Disease Control, ``Recommendations for Prevention
of HIV Transmission in Health-Care Settings,'' Morbidity and
Mortality Weekly Report, 36(2S):3S-18S, 1987.
5. AAMI TIR No. 12-1994, ``Designing, Testing, and Labeling
Reusable Medical Devices for Reprocessing in Health Care Facilities:
A Guide for Device Manufacturers,'' Association for the Advancement
of Medical Instrumentation, 3330 Washington Blvd., suite 400,
Arlington, VA 22201-4598, 1995.
6. Food and Drug Administration, ``Labeling Reusable Medical
Devices for Reprocessing in Health Care Facilities: FDA Reviewer
Guidance,'' Rockville, MD, March, 1995.
List of Subjects in 21 CFR Part 900
Electronic products, Health facilities, Mammography, Medical
devices, Radiation protection, Reporting and recordkeeping
requirements, X-rays.
Therefore, under the Federal Food, Drug, and Cosmetic Act, the
Public Health Service Act, and under authority delegated to the
Commissioner of Food and Drugs, it is proposed that 21 CFR part 900 be
amended to follows:
PART 900--MAMMOGRAPHY
1. The authority citation for 21 CFR part 900 continues to read as
follows:
Authority: Secs. 519, 537, and 704(e) of the Federal Food, Drug,
and Cosmetic Act (21 U.S.C. 360i, 360nn, and 374(e)); sec. 354 of
the Public Health Service Act (42 U.S.C. 263b).
2. Section 900.12 is amended by revising paragraphs (b) and (e) to
read as follows:
Sec. 900.12 Quality standards.
* * * * *
(b) Equipment--(1) Prohibited equipment. Radiographic equipment
designed for general purpose or special nonmammography procedures shall
not be used for mammography. This includes systems that have been
modified or equipped with special attachments for mammography. This
requirement supersedes the implied acceptance of such systems in
Sec. 1020.31(f)(3) of this chapter.
(2) General. All radiographic equipment used for mammography shall
[[Page 14916]]
be specifically designed for mammography and shall be certified
pursuant to Sec. 1010.2 of this chapter as meeting the applicable
requirements of Secs. 1020.30 and 1020.31 of this chapter in effect at
the date of manufacture.
(3) Motion of Tube-Image receptor assembly. (i) Gantry assembly
motion.
(A) The gantry assembly shall be capable of being rigidly fixed in
any position where it is designed to operate. Once fixed in any such
position, the gantry shall not move without operator intervention.
(B) The mechanism assuring compliance with paragraph (b)(2)(A) of
this section shall not fail in the event of power interruption.
(ii) Effective October 1, 2000, the gantry assembly shall allow
continuous rotation of at least 180 deg. from vertical (cranio-caudal
position) in one direction and of at least 105 deg. from vertical in
the other direction.
(iii) Effective October 1, 2005, the gantry assembly shall allow
continuous rotation of at least 180 deg. from vertical (cranio-caudal
position) in one direction and of at least 135 deg. from vertical in
the other direction.
(iv) Effective October 1, 2005, the system shall provide visual
indication of the gantry angle to within 5 deg..
(4) Image receptor sizes. (i) Systems using screen-film image
receptors shall provide, at a minimum, for operation with image
receptors of 18 x 24 centimeters (cm) and 24 x 30 cm.
(ii) Systems using screen-film image receptors shall be equipped
with moving grids matched to all image receptor sizes provided.
(iii) Systems used for magnification procedures shall be capable of
operation with the grid removed.
(iv) Grid motion shall not be impeded when a breast is subjected to
compression during mammography. For each size of breast support device
provided with the system, compliance shall be determined by applying
compression to, and exposing, a 12-cm diameter acrylic disk, 1.5 cm-
thick, placed with its center located 4 cm in from the center of the
chest wall edge of the breast support surface. A 4-cm thick homogeneous
acrylic attenuator with rounded edges shall be located in the beam
between the source and the compression paddle during the exposure. A
film exposed at 28 kilovoltage peak (kVp) to obtain an optical density
as close to 1.3 as possible shall be examined for grid-related
artifacts. For equipment provided with automatic exposure control
(AEC), the test shall be performed in the AEC mode. The compression to
be applied during these tests shall be determined as follows:
(A) Before October 1, 2000, for systems meeting the requirements in
paragraph (b)(12)(i)(C) of this section, the maximum attainable power
driven compression shall be used; and for systems not meeting the
requirements in paragraph (b)(12)(i)(C) of this section, the
compression applied shall be as close to 200 newtons (45 pounds) as
possible, using manual compression or a combination of manual and power
driven compression.
(B) Effective October 1, 2000, the maximum attainable power-drive
compression shall be used to determine compliance.
(5) Beam limitation and light fields. (i) All systems shall have
beam limitation devices that provide means to restrict the useful beam
so that the x-ray field can be adjusted to extend beyond the chest wall
edge of the image receptor.
(ii) Any mammography system with a light field that passes through
the beam-limiting device shall meet the following requirements:
(A) The light field shall be aligned with the x-ray field so that
the total misalignment of the edges of the light field and the x-ray
field along either the length or the width of the visually defined
field at the plane of the breast support shall not exceed 2 percent of
the distance from the source to the midpoint of the chest wall edge of
the image receptor support device.
(B) The light field shall provide an average illumination of not
less than 160 lux (15 footcandles) at 100 cm or the maximum source-
image receptor distance (SID), whichever is less.
(iii) Effective October 1, 2000, all mammography systems shall be
equipped with light fields that pass through the beam-limiting device
and approximate the x-ray field.
(iv) Effective October 1, 2005, all systems shall be interlocked to
prevent exposure unless appropriate combinations of beam limitation and
image receptor size are selected.
(v) Effective October 1, 2005, all systems shall be interlocked to
prevent exposure with an x-ray field that extends beyond the nonchest
wall edges of the image receptor support device.
(6) Source-image receptor distance (SID). Effective October 1,
2000:
(i) Systems designed solely for contact mammography shall have a
minimum SID of at least 55 cm.
(ii) All systems shall provide visual indication of the selected
SID to within 2 percent of its actual value.
(7) Magnification. (i) Systems used for diagnostic procedures shall
have magnification capability available for use by the operator at any
time.
(ii) Systems designed for magnification procedures shall provide at
least one magnification setting within the range of 1.4 to 2.0.
(8) System resolution. (i) The focal spot shall be such that, with
the mammography screen-film combination used in the facility, the
system will provide a minimum resolution of 11 line-pairs/mm when the
high contrast resolution bar pattern is oriented with the bars
perpendicular to the anode-cathode axis, and 13 line-pairs/mm when the
bars are parallel to that axis.
(ii) Effective October 1, 2005, for those systems providing
magnification capability, a focal spot that meets the following
requirements shall be provided:
(A) The resolution provided by the magnification focal spot shall
meet, at a minimum, the requirements of paragraph (b)(8)(i) of this
section. Compliance shall be determined with the test pattern placed
4.5 cm above the magnification breast support, under the conditions of
system magnification providing a magnification factor as close to 1.5
as can be achieved with the system.
(B) When more than one target material is provided, the measurement
in paragraph (b)(8)(ii)(A) of this section shall be made using the
appropriate focal spot for each target material.
(C) The grid shall be removed from the imaging chain during these
measurements.
(9) Focal spot selection. (i) When more than one focal spot is
provided, the system shall indicate, prior to exposure, which focal
spot is selected.
(ii) When more than one target material is provided, the system
shall indicate, prior to exposure, the preselected target material.
(iii) When the target material is selected by the system algorithm,
based on the exposure or a test exposure, the system shall display the
target material selected after the exposure.
(iv) When the selected target is related to the kVp, the system
shall prevent exposure unless the correct combination of target and kVp
is selected.
(10) Focal spot location. (i) The focal spot shall be located so
that the ray falling on the mid-point of the chest wall edge of the
image receptor is within 5 deg. of perpendicular to the
image receptor.
(ii) Compliance shall be determined for each focal spot provided.
(11) Filtration. (i) General. Each system shall comply with the
beam quality requirements of Sec. 1020.30(m)(1)
[[Page 14917]]
of this chapter for the minimum half-value layer (HVL).
(ii) Variable filtration. (A) Effective October 1, 2000, systems
with variable filtration type or thickness shall be interlocked to
prevent exposure if the selected filtration material is inappropriate
for the target chosen or is outside the allowable range specified in
paragraph (b)(11)(i) of this section.
(B) If different types of filtration materials are available, the
system shall display the type of filtration in use prior to exposure.
(C) Effective October 1, 2000, if the filtration is automatically
selected based on a test exposure, the system shall visually indicate
the filtration that was actually used after the exposure is completed.
(12) Compression. All mammography systems shall incorporate a
compression device.
(i) Application of compression. Effective October 1, 2000:
(A) Power driven compression activated by foot controls operable
from both sides of the examinee shall be provided.
(B) Fine adjustment compression controls operable from both sides
of the examinee shall be provided.
(C) The compression device shall provide a maximum compression for
the power drive between 111 newtons (25 pounds) and 200 newtons (45
pounds).
(ii) Decompression. (A) If the system is equipped with a provision
for automatic decompression after completion of an exposure or
interruption of power to the system, the system shall also provide an
override capability to allow maintenance of compression and shall
continuously display the override status.
(B) Each system shall provide a manual emergency compression
release that can be activated in the event of power or automatic
release failure.
(C) If a system is equipped with a remote compression release
control for the operator, the release control shall be located in a
position that allows the operator to observe the examinee during
activation of the release control.
(iii) Compression paddle. (A) Systems shall be equipped with
different sized compression paddles that match the sizes of all full-
sized image receptors provided. Compression paddles for special
purposes, including those smaller than the full size of the image
receptor (for ``spot compression'') may be provided. Such compression
paddles for special purposes are not subject to the requirements of
paragraphs (b)(12)(iii)(B) and (b)(12)(iv)(A) of this section.
(B) When compression is applied, the compression paddle shall be
flat and parallel to the breast support table and shall not deflect
from parallel by more than 1.0 cm at any point on the surface of the
compression paddle. Compliance shall be determined by applying maximum
system power compression to a 12-cm diameter acrylic disk 1.5-cm thick
placed with its center located 4 cm in from the center of the chest
wall edge of the breast support surface for each full size compression
paddle provided. For systems without power driven compression, or for
systems which, before October 1, 2000, do not meet the requirements in
paragraph (b)(12)(i)(C), compliance shall be determined by applying
compression at as close to 200 newtons (45 pounds) as achievable using
manual or a combination of manual and power driven compression.
Vertical measurements shall be made between the breast support surface
and the compression paddle at each of the four corners of the image
receptor and shall be compared to each other and to the 1.5-cm
thickness of the test device. The maximum difference between any two
values shall not exceed 1.0 cm.
(C) The chest wall edge of the compression paddle shall be straight
and parallel to the edge of the image receptor.
(D) The chest wall edge should be bent upward, forming a lip to
allow for examinee comfort, but shall not interfere with the image at
the chest wall.
(iv) Compression paddle alignment. (A) Effective October 1, 2000,
when compression is applied, a line constructed perpendicular to the
flat surface of the compression paddle through the vertex of the angle
formed by the flat surface and the lip of the compression paddle and
extending to the plane of the image receptor, shall intercept that plan
within a distance no greater than 1 percent of the SID
from the useful edge of the image receptor at the chest wall side (see
Figure 1).
BILLING CODE 4160-01-P
[GRAPHIC] [TIFF OMITTED] TP03AP96.000
(B) Effective October 1, 2005, when compression is applied, a line
constructed perpendicular to the flat surface of the compression paddle
through the vertex of the angle formed by the flat surface and the lip
of the compression paddle and extending to the plane of the image
receptor, shall pass within 2 millimeters of the useful
[[Page 14918]]
edge of the image receptor at the chest wall side.
(C) When the system is configured without magnification capability,
compliance shall be determined with the bottom surface of the
compression paddle placed at a distance within the range of 2.0 to 6.0
cm above the breast support.
(D) When the system is configured for magnification procedures,
compliance shall be determined with the bottom surface of the
compression paddle placed at a distance within the range of 2.0 to 6.0
cm above the breast support of the magnification device.
(v) Display of compressed breast thickness. Effective October 1,
2005, the compressed breast thickness shall be displayed and visible to
the operator during positioning.
(A) The compressed breast thickness shall be displayed to within
0.5 cm.
(B) Compliance shall be determined at the maximum attainable power
compression using a flat sheet of rigid material with known thickness
placed between the examinee support and the compression device. This
sheet shall be placed in flat contact with the top surface of the
breast support. If the support is uneven or has projections around the
edges, the sheet shall be in contact with that part of the surface that
actually supports the breast. This test shall be performed using sheets
of the following thicknesses: 3 cm, 4.5 cm, and 6 cm.
(13) Technique factor selection and display. (i) Manual selection
of milliampere seconds (mAs) shall be available.
(ii) All technique factors shall be clearly displayed at the
control panel prior to exposure.
(iii) When operating in AEC mode, the system shall indicate initial
technique factors prior to exposure.
(iv) Following AEC mode use, the system shall indicate the actual
kVp and mAs used during the exposure.
(v) All indications of kVp shall be within 5 percent of
the actual kVp.
(vi) Effective October 1, 2005:
(A) Each system shall provide, at a minimum, for the selection of
tube potentials of between 22 and 34 kVp.
(B) Selection of kVp shall be available in increments no greater
than 1 kilovolt each over the entire range provided.
(C) Adjacent mAs settings shall differ by no more than 26 percent
of the lower of the adjacent settings.
(D) Combinations of exposure time and tube current (mAs) shall be
available over the range of at least 5 mAs to 300 mAs.
(14) Radiation output. (i) The system shall be capable of producing
a minimum output of 1.29 x 10-4 coulomb/kilogram (C/kg) per second
(500 milliroentgen (mR) per second) when operating at 28 kVp in the
standard mammography mode at any SID where the system is designed to
operate. Effective October 1, 2000, the system shall be capable of
producing a minimum output of 2.06 x 10-4 C/kg per second (800 mR
per second) when operating at 28 kVp in the standard mammography mode
at any SID where the system is designed to operate.
(ii) The system shall be capable of maintaining the required
minimum radiation output for at least 3.0 seconds.
(iii) Compliance shall be determined with the center of the
detector located 4.5 cm above the breast support device used for
contact mammography and centered on the breast support 4 cm in from the
chest wall edge of the support with the compression paddle in place
between the source and the detector.
(15) Automatic exposure control. (i) Each system shall provide an
AEC mode which is operable in all combinations of equipment
configuration provided, i.e. grid, nongrid; magnification,
nonmagnification; and various target-filter combinations.
(ii) The AEC shall be capable of providing automatic mAs selection.
(iii) The AEC shall provide reproducible radiation exposures with a
coefficient of variation not to exceed 0.05.
(iv) The positioning or selection of the active detector shall
permit flexibility in the placement of the detector under the target
tissue.
(A) The size and available positions of the detector shall be
clearly indicated at the input surface of the breast compression
paddle.
(B) The selected position of the detector shall be clearly
indicated and visible from both sides of the examinee.
(v) The system shall provide means for the operator to vary the
selected optical density from the normal (zero) setting.
(vi) Effective October 1, 2005, the system shall provide means for
the operator to vary the optical density a minimum of 4 steps above and
4 steps below the normal (zero) setting of optical density. These steps
shall vary in optical density increments of between 10 to 20 percent of
the difference between adjacent mAs settings;
(vii) The system shall meet, at a minimum, the following
requirements at all detector positions and for thicknesses of 2, 4, and
6 cm of homogeneous breast tissue-equivalent material. Compliance shall
be determined using the screen-film and processing combination used at
the facility when the mean optical density is at least 1.20.
(A) Effective October 1, 2000, equipment shall produce images with
optical densities that vary from the mean optical density by no more
than 0.30.
(B) Effective October 1, 2005, equipment shall produce images with
optical density that varies from the mean optical density by no more
than 0.15.
(16) Disabled examinees. Each facility scheduling disabled
individuals shall have equipment and established protocols to ensure
the facility's capability to perform mammography adequately on such
individuals.
(17) X-ray film. The facility shall use x-ray film for mammography
that has been designated by the film manufacturer as appropriate for
mammography.
(18) Intensifying screens. The facility shall use intensifying
screens for mammography that have been designated by the screen
manufacturer as appropriate for mammography and shall match them to the
spectral sensitivity specified by the manufacturer of the film used.
(19) Film processing solutions. For processing mammography films,
the facility shall use chemical solutions that are capable of
developing the films used in a manner equivalent to the minimum
requirements specified by the film manufacturer.
(20) Lighting. The facility shall provide a special light with
variable luminance capable of producing light levels greater than that
provided by the view box.
(21) Film Masking Devices. (i) All facilities shall have film
masking devices that can limit the illuminated area to a region equal
to or smaller than the exposed portion of the film.
(ii) Facilities using x-ray collimation that provides
nonrectangular exposed areas on the film shall provide masking devices
appropriate to these fields.
(iii) Facilities shall make devices meeting the requirements of
paragraphs (b)(21)(i) and (b)(21)(ii) of this section available to the
interpreting physician.
(22) Film processors. Film processors used to develop mammograms
shall meet the following requirements:
(i) The processor shall be adjusted and maintained to meet the
technical development specifications for the mammography film in use.
(ii) Effective October 1, 2000, the processor shall indicate the
selected time cycle reflecting the time from leading edge entry into
the developer to leading edge entry into the fixer.
[[Page 14919]]
(iii) Effective October 1, 2000, the processor shall be capable of
maintaining the developer temperature to within 0.3 deg.
Celsius (0.5 deg.F). Compliance measurements for immersion
tank type processors shall be taken at the center of the surface of the
developer solution and 7.5 cm (3 inches) below the surface when the
developer is at the proper operating level.
(iv) Effective October 1, 2005, the processor shall clearly display
the actual developer temperature to within 0.1 deg.C
(0.2 deg.F) of the actual temperature.
(v) Effective October 1, 2005, for processors with variable cycles,
the selectable parameters shall be interlocked to prevent any
initiation of changes in the parameters until any film in process is
completed, and to prevent any new film from entering the process cycle
until the variables are properly stabilized at the new cycle
parameters. If the unit is equipped with an override of this interlock
for maintenance procedures, the override status shall be clearly
indicated to the operator.
* * * * *
(e) Quality assurance--equipment--(1) Daily quality control tests.
Facilities with screen-film systems shall perform a processor
performance test on each day that examinations are performed before any
examinations are performed that day. The test shall include an
assessment of base plus fog density, mid-density, and density
difference, using the mammography film used clinically at the facility.
(i) The base plus fog density shall be within + 0.03 of the
established operating level.
(ii) The mid-density shall be within 0.15 of the
established operating level of no less than 1.20 optical density (OD).
(iii) The density difference shall be within 0.15 of
the established operating level.
(2) Weekly quality control tests. Facilities with screen-film
systems shall perform an image quality evaluation test at least weekly.
(i) The optical density of the film at the center of an image of a
standard FDA-accepted phantom shall be at least 1.20 when exposed under
a typical clinical condition.
(ii) The optical density of the film at the center of the phantom
image shall not change by more than 0.20 from the
established operating level.
(iii) The phantom image shall achieve at least the minimum score
acceptable to FDA in accordance with Sec. 900.3(d) or Sec. 900.4(a)(9).
(iv) The image contrast between the background of the phantom and
an added test object, used to assess density difference, shall be
measured and shall not vary by more than 0.05 from the
established operating level.
(3) Quarterly quality control tests. Facilities with screen-film
systems shall perform the following quality control tests at least
quarterly:
(i) Fixer retention in film. The residual fixer shall be no more
than 5 micrograms per square cm.
(ii) Repeat analysis. If the total repeat or reject rate changes
from the previously determined rate by more than 2.0 percent of the
total films included in the analysis, the reason(s) for the change
shall be determined and any corrective actions and their results shall
be recorded.
(4) Semiannual quality control tests. Facilities with screen-film
systems shall perform the following quality control tests at least
semiannually:
(i) Darkroom fog. The optical density attributable to darkroom fog
shall not exceed 0.05 when a mammography film of the type used in the
facility, which has a mid-density of no less than 1.2 OD, is exposed to
typical darkroom conditions for 2 minutes while such film is placed on
the counter top. If the darkroom has a safelight, it shall be on during
this test.
(ii) Screen-film contact. Testing for screen-film contact shall be
conducted using 40 mesh screen.
(iii) Compression. The compression device shall meet the
specifications described in Sec. 900.12(b)(12).
(5) Annual quality control tests. Facilities with screen-film
systems shall perform the following quality control tests at least
annually:
(i) Automatic exposure control performance. (A) The AEC shall be
capable of maintaining film optical density within 0.30 of
the mean optical density when phantom thickness is varied over a range
of 2 to 6 cm and the kVp is varied over the kVp range used in the
facility for such thicknesses.
(B) The operating optical density of the film in the center of the
phantom image shall not be less than 1.20.
(C) If the requirement of paragraph (e)(5)(i)(A) of this section
cannot be met, a technique chart shall be developed showing appropriate
techniques (kVp and density control settings) for different breast
thicknesses and compositions that must be used so that optical
densities within 0.30 of the average under phototimed
conditions can be produced.
(ii) Kilovoltage peak (kVp) accuracy and reproducibility.
(A) At the lowest and highest clinical values and at any other
commonly used clinical settings of kVp, the kVp shall be accurate to
within 10 percent, and
(B) At the most commonly used clinical settings of kVp, the
coefficient of variation of reproducibility of the kVp shall be equal
to or less than 0.02.
(iii) System Resolution. The limiting spatial resolution shall not
be less than 13 line-pairs/mm parallel to the anode-cathode axis of the
x-ray tube and 11 line-pairs/mm perpendicular to the anode-cathode
axis.
(iv) Beam quality and half-value layer (HVL). The HVL shall meet
the specifications in paragraph (b)(11) of this section.
(v) Breast entrance exposure and AEC reproducibility. The
coefficient of variation for both exposure and mAs shall not exceed
0.05.
(vi) Dosimetry. The average glandular dose delivered during a
single cranio-caudal view of an FDA-accepted phantom simulating a 4.2-
cm thick, compressed breast consisting of 50 percent glandular and 50
percent adipose tissue, shall not exceed 3.0 milliGray (0.3 rad) per
exposure. The dose shall be determined with technique factors and
conditions used clinically for a 4.2-cm, 50 percent glandular/50
percent adipose tissue compressed breast.
(vii) X-ray field/light field/image receptor/compression paddle
alignment. The x-ray field/light field/image receptor alignment shall
meet the specifications of paragraph (b)(5) of this section and
Sec. 1020.31(f)(3) of this chapter. In addition, the chest wall edge of
the compression paddle shall not extend beyond the chest wall edge of
the image receptor by more than one per cent of the SID.
(viii) Screen speed uniformity. Screen speed uniformity of all the
cassettes in the facility shall be tested and the difference between
the maximum and minimum optical densities shall not exceed 0.30. Screen
artifacts shall also be evaluated during this test.
(ix) System artifacts. System artifacts shall be evaluated with a
high-grade, defect-free phantom large enough to cover the mammography
cassette.
(6) Quality control tests--other modalities. For systems with
image receptor modalities other than screen-film, the quality assurance
program shall be substantially the same as the quality assurance
program recommended by the image receptor manufacturer, except that the
maximum allowable dose shall not exceed the maximum allowable dose for
screen-film systems in paragraph (e)(5)(vi) of this section.
[[Page 14920]]
(7) Mobile Units. The facility shall verify that mammography units
used to produce mammograms at more than one location meet the
requirements in paragraphs (e)(1) through (e)(6) of this section. In
addition, at each examination location, before any additional
examinations are conducted, the facility shall verify satisfactory
performance of such units using a test method that establishes the
adequacy of the image quality produced by the unit.
(8) Use of test results. (i) After completion of the tests
specified in paragraphs (e)(1) through (e)(7) of this section, the
facility shall compare the test results to the corresponding specified
action limits; or, for non screen-film modalities, to the
manufacturer's recommended action limits; or, for post-move, pre-
examination testing of mobile units, to the limits established in the
test method used by the facility. The applicable tests shall be
repeated immediately for any parameters found to be beyond the
specified acceptable ranges.
(ii) If the repeated tests continue to produce unacceptable
results, the source of the problem shall be identified and corrective
actions shall be taken before any further examinations are performed.
(9) Surveys. (i) At a frequency of no less than once a year, each
facility shall undergo a survey by a medical physicist or by an
individual under the direct supervision of a medical physicist. At a
minimum, this survey shall include the performance of tests to ensure
that the facility meets the quality assurance requirements of the
annual tests in paragraphs (e)(5) and (e)(6) of this section and the
weekly phantom image quality test in paragraph (e)(2) of this section.
(ii) The results of all tests conducted by the facility in
accordance with paragraphs (e)(1) through (e)(7) of this section, as
well as written documentation of any corrective actions taken and their
results, shall be evaluated for adequacy by the medical physicist
performing the survey.
(iii) The medical physicist shall prepare a survey report that
includes a summary of this review and recommendations for necessary
improvements.
(iv) The survey report shall be sent to the facility within 30 days
of the date of the survey.
(v) The survey report shall be dated and signed by the medical
physicist performing or supervising the survey. If the survey was
performed entirely or in part by another individual under the direct
supervision of the medical physicist, that individual and the part of
the survey that individual performed shall also be identified in the
survey report.
(10) Mammography equipment evaluations. Additional evaluations of
mammography units or image processors shall be conducted whenever a new
unit or processor is installed, or major components of a mammography
unit or processor equipment are changed. These evaluations shall be
used to determine whether the new or changed equipment meets the
requirements of applicable standards in paragraphs (b) and (e) of this
section. All problems shall be corrected before the new or changed
equipment is put into service for examinations. The mammography
equipment evaluation shall be performed by an individual whose
qualifications are adequate to examine equipment for this purpose and
in accordance with procedures that are adequate to ensure that the
examination is complete and accurate.
(11) Facility cleanliness. (i) The facility shall establish and
implement adequate protocols for maintaining darkroom, screen, and view
box cleanliness.
(ii) The facility shall document that all cleaning procedures are
performed at the frequencies specified in the protocols.
(12) Calibration of exposure measuring instruments. (i) Instruments
used to measure the exposure or exposure rate from a mammography unit
shall be traceable to a national standard.
(ii) Effective October 1, 2005, the manufacturers calibrating
instruments to measure exposure or exposure rate from mammography units
shall meet the requirements of a recognized quality assurance program.
A calibration laboratory calibrating instruments to measure exposure or
exposure rate from mammography units must be accredited by a recognized
national program or an equivalent international program which requires
continuing participation with NIST in measurements and testing for
maintaining quality assurance appropriate for mammography.
(13) Infection control. Facilities shall establish and comply with
a system specifying procedures to be followed by the facility for
cleaning and disinfecting mammography equipment after contact with
blood or other potentially infectious materials. This system shall
specify the methods for documenting facility compliance with the
infection control procedures established and shall:
(i) Comply with all applicable Federal, State, and local
regulations pertaining to infection control; and
(ii) Comply with the manufacturer's recommended procedures for the
cleaning and disinfection of the mammography equipment used in the
facility; or
(iii) If adequate manufacturer's recommendations are not available,
comply with generally accepted guidance on infection control, until
such recommendations become available.
Dated: March 22, 1996.
David A. Kessler,
Commissioner of Food and Drugs.
Donna E. Shalala,
Secretary of Health and Human Services.
[FR Doc. 96-7833 Filed 3-29-96; 8:45 am]
BILLING CODE 4160-01-P