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Mammography Regulatory Issues
Bruce MatkovichRadiation Safety Section
Michigan Dept. Of Consumer & Industry Services
September 19, 2001
CIS – Radiation Safety Section 2
Outline Mammography overview Regulatory history Inspection results The future Questions
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Mammography Overview Mammography is radiography of
the breast Need to use appropriate energy
spectrum Need high image resolution Specialized equipment
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MammographyMachine
X-Ray Tube
Compression Paddle
Film Holder
Foot Peddles
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Regulatory History 1988 – American College of
Radiology’s Mammography Accreditation Program Voluntary
1989 – Michigan Public Act 56 Essentially required ACR accreditation Outlawed general purpose machines
1991 – Annual state inspections begin
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Regulatory History – Cont. 1992 – Federal Mammography Quality
Standards Act (MQSA) Nationwide mammography standards
1993 – State of Michigan mammography rules Standards for technologists and physicists QC and equipment standards
1994 – Michigan Public Act 100 Physician qualifications Interpreters must be board certified
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Regulatory History – Cont. 1994 – MQSA interim regulations 1995 – MQSA inspections begin 1999 – MQSA final regulations
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Inspections Inspections involve:
Equipment checks Personnel credentials review Quality control records review Image processing evaluation
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Inspections – Cont. Inspections are scheduled in
advance Typical inspection of a one-machine
facility is 4 to 5 hours MQSA inspection fee is $1549 for a
one-machine facility Michigan inspection fee is $127.88
per tube
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Inspection Results – Equipment Common problems:
Collimation problems (typically problems found with alignment of collimator light to x-ray field)
Automatic exposure control (AEC) tracking (maintaining consistent film darkness with varying patient thickness and density)
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CollimationTest
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AEC Test
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Inspection Results –Personnel Credentials Common problems:
Lack of documentation to verify compliance with continuing experience or continuing education requirements
Occasionally find personnel that are not qualified
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Inspection Results –Quality Control Common problems:
Failure to perform testing at required intervals
Failure to take corrective action when out of limits
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Personnel and QC Records Review
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Inspection Results –Image Processing Common problems:
Under processing – determined using the Sensitometric Technique for the Evaluation of Processing (STEP)
STEP compares the facility’s processor to an optimized processor
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Phantom Image and Dose Mammography phantom image
quality and mean glandular dose are important aspects of inspection
Phantom image and dose are obtained simultaneously using clinical techniques for average patient
Phantom image quality and dose are usually found to be in compliance
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Phantom and Dose Testing
Dosimeter
Mammography Phantom
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PhantomImage
Fibers
Speck Groups
Masses
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Phantom Image Failure Rates
0%
5%
10%15%
20%
25%
30%35%
40%
45%
Ja
n-8
8
Ja
n-8
9
Ja
n-9
0
Ja
n-9
1
Ja
n-9
2
Ja
n-9
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Ja
n-9
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Ja
n-9
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Ja
n-9
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Ja
n-9
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Ja
n-9
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Ja
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9
Ja
n-0
0
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n-0
1
Ph
an
tom
Ima
ge
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ilure
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Failure Rate
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Mean Glandular Dose 200 millirads per view is the State
of Michigan dose limit for an average-size patient
300 millirads per view is the federal and ACR dose limit for an average-size patient
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Mean Glandular Dose – Cont. Changes in imaging technology are
driving doses up Michigan’s low dose limit is
controversial Michigan does not want to obstruct
image quality improvement
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Average Mammography Doses
100120140160180200
Year
Mill
ira
ds
Michigan Doses MQSA Nationwide Doses
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The Future Digital mammography
Only one FDA approved manufacturer currently
Must be used in a facility that has a screen-film unit
Digital advantages Digitally enhance images No film or wet chemistry processing
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The Future – Cont. FDA regulations that take effect
October 28, 2002: AEC must track to within ±0.15 OD of
mean OD (currently ±0.30 OD) Radiation output must be 800 mR/sec
at 28 kVp (currently 513 mR/sec)
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The Future – Cont. More FDA regulations that take
effect October 28, 2002: Compression device must have fine
adjustment Maximum compression force for the
power drive must be at least 25 lbs. and not more than 45 lbs.
Medical physicist must evaluate system resolution
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The Future – Cont. Proposed Michigan statute revisions
to improve consistency with federal mammography standards: “Medical director” to become “lead
interpreting physician” Physician initial experience and
continuing experience requirements same as MQSA
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The Future – Cont. Proposed Michigan statute revision
for a surety requirement to insure that patient records are available even if a facility closes.
Dose limit in the Ionizing Radiation Rules would probably be changed
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For More Information
Radiation Safety Websitehttp://www.cis.state.mi.us/bhs/rss
FDA’s Mammography Websitehttp://www.fda.gov/cdrh/
mammography/
