Fluoroscopy
Safety
New Wisconsin Regulations
In 2010, WI enacted new training regulations for clinicians
who use fluoroscopy. Unless certified by the American
Board of Radiology (or board eligible), clinicians are
required to be trained in:
•Principles of operation of the fluoroscopic x-ray system
•Biological effects of x-rays
•Principles of radiation protection
•Fluoroscopic outputs
•High Level control options
•Dose reduction techniques
•Applicable state and federal regulations
What is Fluoroscopy?
Fluoroscopy is an imaging procedure that uses a
continuous x-ray beam to create real-time
images viewed on a monitor.
It enables physicians to view internal organs and
vessels in motion.
Fluoroscopy is used in both diagnostic and
therapeutic procedures.
Medical uses of fluoroscopy
began shortly after Roentgen’s
discovery of x-rays in 1895.
Fluoroscopy Today
Fluoroscopy for
tuberculosis (1940)
1990’s: Injuries Reported to FDA
From 1992 through 1995, the FDA received
more than 100 reports of patients with
radiation injuries from fluoroscopy.
Since 1992, reports of injuries to patients
and physicians have appeared in radiology,
cardiology, and medical physics journals.
What Kind of Injuries?
Skin Injury and Time to Onset
Listed in order of time of initial onset
Effect
Approximate
Threshold
Dose (Gy)
Time of
Initial
Occurance
Note
Early
transient
erythema
2
Hours
Inflammation of the skin caused by
activation of a proteolytic enzyme that
increases the permeability of the capillaries
Acute
ulceration
20
< 2 weeks
Early loss of the epidermis that results from
the death of fibroblasts and endothelial
cells in interphase
Epilation
3
2 to 3 weeks
Hair loss caused by the depletion of matrix
cells in the hair follicles; permanent at
doses exceeding 6 Gy
Dry
desquamation
8
3 to 6 weeks
Atypical keratinization of the skin caused by
the reduction of the number of clonogenic
cells within the basal layer of the epidermis
Skin Injury and Time to Onset
Effect
Approximat
Time of
e Threshold
Initial
Dose (Gy) Occurance
Note
Main erythema
3
Days to
Weeks
Inflammation of the skin caused by
hyperemia of the basal cells and subsequent
epidermal hypoplasia
Moist
desquamation
15
4 to 6
weeks
Loss of the epidermis caused by sterilization
of a high proportion of clonogenic cells within
the basal layer of the epidermis
Secondary
ulceration
15
> 6 weeks
Late erythema
20
8 to 20
weeks
Secondary damage to the dermis as a
consequence of dehydration and infection
when moist desquamation is severe and
protracted
Inflammation of the skin caused by injury of
the blood vessels; edema and impaired
lymphatic clearance precede a reduction in
blood flow
Skin Injury and Time to Onset
Effect
Approximate
Time of
Threshold
Initial
Dose (Gy)
Occurance
Dermal
necrosis
20
>10
Weeks
Invasive
fibrosis
20
Month to
years
Dermal
atrophy
10
> 26
Weeks
Note
Necrosis of the dermal tissues as a
consequence of vascular insufficiency
Method of healing associated with acute
ulceration, secondary ulceration, and dermal
necrosis, leading to scar tissue formation
Thinning of the dermal tissues associated
with the contraction of the previously
irradiated area
Source: Centers for Disease Control and Prevention. Cutaneous radiation
injury: fact sheet for physicians.
Example 1
A 40-year-old male underwent coronary
angiography, coronary angioplasty and a
second angiography procedure due to
complications, followed by a coronary
artery by-pass graft, all on March 29,
1990.
Example and images provided by Thomas Shope, U.S. FDA Center for
Devices and Radiological Health
6-8 weeks post procedure
Note the erythema in
the shape of the
radiation collimation
16-21 weeks post procedure
Erythema reduced,
Secondary Damage
(not as well imaged)
18-21 months post procedure
Close-up view
of lesion
Post Skin Graft
Note Epilation
Example 2
Injury following three procedures
involving transjugular intrahepatic
portosystemic shunt placement
(TIPS), demonstrating
disfigurement after surgical
correction.
Koenig TR, Wolff D, Mettler FA et al. Skin injuries
from fluoroscopically guided procedures: part 1,
characteristics of radiation injury. AJR Am J
Roentgenol 2001; 177(1):3-11.
Example 3
Injury to arm of patient.
Patient was draped for
procedure and physicians
did not realize that she
had moved her arm so that
it was resting on the port of
the X-ray tube during the
procedure.
Wagner LK, Archer BR. Minimizing Risks from Fluoroscopic X Rays. 4th
edition.
The Woodlands, Texas: Partners in Radiation Management, 2004.
Why Are Injuries Occurring?
One contributing factor is the growth in number and types
of interventional procedures using fluoroscopy. But any
procedure using fluoroscopy has the potential for patient
injury.
Another factor may be more overweight and obese
patients. Higher energy x-rays and higher radiation dose
rates are required to penetrate through these patients.
FDA Actions
In 1994, the FDA issued a Public Health
Advisory on avoidance of serious skin
injuries to patients during fluoroscopyguided procedures.
In 1995, the FDA issued a follow-up
advisory on recording information in the
patient’s record that identifies the
potential for serious skin injury from
fluoroscopy.
Joint Commission Action
In 2006, the Joint Commission added a Sentinel Event
category for radiation overdose involving prolonged
fluoroscopy with a cumulative dose of more than 15 Gray
to a single field.
Fluoroscopy machines manufactured after June 2006
measure and display a reference patient radiation dose.
The reference dose can be monitored during the
procedure, and the cumulative dose can be recorded in
the patient’s medical record.
Summary
All of the following injuries can be
caused by radiation:
– Skin erythema and desquamation
– Epilation
– Skin ulceration
What About Personnel Safety?
Physicians and staff using fluoroscopy are exposed
to:
- Scattered radiation from the patient
- Leakage radiation from
the x-ray tube
Detector/image intensifier
- Primary radiation from the
x-ray beam if their hands
are in the radiation field
x-ray tube
Personnel Safety
Although clinician radiation dose is much
lower than the patient dose, it is proportional
to patient dose.
Higher patient doses will usually lead to
higher operator and staff doses.
Radiation Risks
High doses of radiation (>1 Gray in a single
exposure), such as those received by patients
injured by fluoroscopy, are linked to skin injury
and increased risk of cancer.
Low doses of radiation over long periods of time,
such as those received by medical personnel,
may result in an increased risk of cancer,
although this has not been conclusively proven.
ALARA
(As Low As Reasonably Achievable)
Because we know that large doses of radiation
can cause long term health effects, such as
increasing the risk of developing cancer, we
assume that all radiation exposure entails some
risk.
Therefore, we should try to limit the radiation
exposure to patients and staff, consistent with
obtaining the necessary clinical information.
In fluoroscopy, there are three practical techniques to
reduce radiation exposure to patients and personnel.
•Reduce Fluoro Time
•Increase Distance
•Provide Shielding
The following slides demonstrate how to use these
techniques to reduce radiation exposure.
Time: Identify if the patient has had
other recent long fluoro procedures
Check the patient’s medical record to see if they have
had a recent long fluoroscopy procedure in the same
location.
If yes, try to change the C-Arm angle so that you are
not irradiating the same area of skin again.
Time: Recognize the Fluoroscopy
“Beam-On” Controls
Typical x-ray
“beam-on” foot
pedal.
Most units also
have a beam-on
button or switch the
user can operate
by hand.
Time: Minimize “Beam-On” time
Use short taps of the fluoroscopy beam-on
control. Don’t use a “lead foot” on the
fluoroscopy pedal.
Reducing beam-on
time is the most
effective way to
reduce dose.
Time: LIH and LFH
Use Last Image Hold (LIH) or
Last Fluoroscopy Hold (LFH)
when possible instead of reexposing the patient.
Last Image Hold saves the last fluoroscopy image
and displays it on the monitor.
Last Fluoroscopy Hold saves the last video
sequence of fluoroscopy images for instant replay.
Time: Fluoroscopy Dose Modes
Different dose mode selections may be
available
– Low Dose (↓patient dose, ↑ image noise)
– High Dose (↑patient dose, ↓ image noise)
– Low Frame Rate (↓patient dose, ↓ frame rate)
When Image Quality allows, use low dose
mode and/or a lower frame rate.
Time: Minimize Use of High Dose
Mode
High dose rate
mode may be
needed for large
patients or for
seeing greater
detail.
High dose mode
selection is
usually denoted
by a “+” sign.
Do not routinely use high dose mode.
Time: Digital Acquisition Mode
X-Ray machines used for
interventional procedures have a
digital acquisition or “cine” mode.
A high radiation dose rate is used to obtain a
series of high resolution images with reduced
image noise.
The radiation dose per frame for digital
acquisitions can be 15 times greater than for
fluoroscopy.
Time: Use Digital Acquisition/Cine
Mode Appropriately
The number and length of digital
acquisition or cine “runs” may be
the greatest source of patient
radiation dose in interventional
radiology procedures.
Be aware of the increased dose rate and do not
use digital acquisition/cine mode as a substitute
for fluoroscopy.
Using Time to Reduce Exposure:
Summary
When image quality allows, choosing to
use low dose fluoro modes and last
image hold, while limiting the use of
“boost” fluoro and high dose digital
acquisitions, will reduce patient and
staff radiation exposure.
Distance: Scattered Radiation
Detector/Image Intensifier
x-ray tube
During fluoroscopy,
radiation is scattered
from the surface of the
patient where the x-ray
beam enters.
Scattered radiation is the
main source of radiation
dose to staff. It also
decreases image
contrast and degrades
image quality.
Distance: C-Arm Position
Image Intensifier
Position the X-ray tube
underneath the patient, not
above the patient.
The greatest amount of
scatter radiation is produced
where the x-ray beam
enters the patient.
X-ray Tube
By positioning the x-ray tube
below the patient, you
receive less scatter
radiation.
Distance: C-Arm Position
Always stand closer to the
detector/image intensifier.
For lateral and oblique
projections, position the
C-arm so that the x-ray
tube is on the opposite
side of the patient from
where you are working.
This will reduce the
scatter radiation
reaching you.
Always stand farther from the XRay Tube.
Distance: C-Arm Position
Position the x-ray tube and
image intensifier so you are
working on the image
intensifier side of the patient.
Position the x-ray tube as far
from the patient as possible.
Position the Image intensifier
as close to the patient as
possible.
X-ray tube
Image intensifier
Distance: Proximity to the X-Ray
Tube
The patient’s skin should
never touch or be near the xray tube port (where the xrays come out).
Staff should also never touch
or be near the x-ray tube
port.
Burns can occur in seconds if
skin is touching or near the xray tube port.
X-ray tube port
Distance: Minimize the Air Gap
Move the detector or
image intensifier as
close to the patient as
possible.
A smaller air gap
reduces radiation dose
to the patient and staff
and improves image
quality.
Distance: When possible increase
your distance from the patient when
the x-ray beam is on
When possible, simply taking
a step back from the
radiation source whenever
possible will greatly reduce
your radiation dose.
Moving from 30cm to 60 cm
from the patient will reduce
your exposure by a factor of
4.
Distance: Stay Out of the
Fluoroscopy Beam
Don’t put your hands in the fluoroscopy beam unless
absolutely necessary for the procedure.
This is the hand of a
physician who was
exposed to repeated small
doses of x-ray radiation for
15 years. The skin cancer
appeared several years
after his work with x-rays
had ceased.
Meissner, William A. and Warren, Shields: Neoplasms, In Anderson
W.A.D. editor; Pathology, edition 6, St. Louis, 1971, The C.V. Mosby Co
Using Distance to Reduce Exposure:
Summary
• When possible, always position the image
•
•
•
•
intensifier over the patient.
Maximize the distance from the x-ray tube to the
patient.
Move the image intensifier as close to the patient
as you can.
Maximize the distance between you and the patient
during the x-ray exposure.
Do not put your hands in the primary beam.
Shielding: Collimate Appropriately
uncollimated
collimated
Collimate tightly to the
area of clinical interest to
reduce patient and staff
dose, reduce scatter, and
improve image contrast.
Shielding: Magnification Modes
Magnification enlarges the anatomy being viewed, but it
also increases the radiation dose to the patient.
Multiple electronic magnification modes may be available.
Use Shielding
Wisconsin DHS regulations require anyone
within 6 feet of a fluoroscopy machine to wear
a lead apron.
You may also wear a lead thyroid shield or
leaded eyeglasses, depending on the type
and amount of work you do.
Shielding: Mini C-Arms
Although Mini C-Arms produce less
scatter Radiation than full C-Arms,
Aspirus Wausau Hospital radiation
safety procedures require the use of
lead aprons when performing any
fluoroscopy procedure.
GE OEC Mini-C
Shielding: Hang Lead Aprons
Properly
Hanging lead aprons on
hangers/hooks prevents
the lead from cracking
and tearing.
This is for your safety,
so please be sure to
take care of your lead.
Using Shielding to Reduce Exposure:
Summary
• Collimate the radiation to the area of
interest.
• Minimize the use of high magnification
modes.
• Always wear radiation protection devices.
Pediatric Patients
Children are estimated to be two to seven times
more sensitive to radiation than adults.
They have more dividing and differentiating cells and
have a longer time over which radiation effects such
as cancer can appear.
Use techniques taught in this course to minimize the
dose to pediatric patients as well.
To Reduce Pediatric Radiation
Exposure
•
•
•
•
•
•
Use low dose or low pulse rate mode.
Collimate the beam to only show the area of
interest.
Maximize the distance from the x-ray tube to the
patient.
Minimize the distance from the image intensifier
to the patient.
Use the minimum electronic magnification
necessary.
Use the minimum amount of “beam-on” time
necessary.
Radiation Dose Limits
Occupational radiation exposure to radiation workers
is regulated by the federal government and the
states.
Annual occupational radiation exposure limits are set
to levels at which there is believed to be negligible
risk of biological effects.
Whole Body:
Lens of the Eye:
Extremities, Skin:
50 mSv/yr
150 mSv/yr
500 mSv/yr
Dosimetry Badges
Workers likely to receive an occupational
radiation dose greater than 5 mSv/year
must be monitored.
Radiation exposure reviews determine
which categories of workers are required to
be monitored.
Workers with particular concern regarding
radiation, such as pregnant workers, may
also be monitored even if they are not likely
to exceed 5 mSv/yr.
Dosimetry
Badge
Dosimetry Badges
If you have been issued a single
dosimetry badge, wear it outside
your lead apron at collar level.
If you have been issued two
badges, wear the “collar badge”
outside your lead apron, and wear
the “body badge” underneath your
lead apron.
For More Information
These and other policies regarding radiation safety are
available in the Aspirus Wausau Hospital Radiation
Safety Plan which is available on the hospital network
at:
S:\Radiation Safety Plan
or by contacting the Aspirus Wausau Hospital
Radiation Safety Officer.
Questions
For questions about fluoroscopy safety, contact
the Aspirus Wausau Hospital Radiation Safety
Officer.
Raymond Wery, M.S., DABR
phone: 715-847-2031
rayw@aspirus.org
Fluoroscopy Safety Certificate
A test will follow this presentation, to validate your
understanding of these safety principles.
If you would like a certificate documenting that you
have received training in Fluoroscopy Safety, call or
e-mail the Aspirus Wausau Hospital Provider Support
Services Department.
The certificate can satisfy other organizations’
requirements for fluoroscopy training, if needed.
Contributors
Mary Ellen Jafari, M.S., DABR
Alan M. Daus., M.S., DABR
Diagnostic Medical Physics Section
Imaging Department
Gundersen Lutheran Medical Center
La Crosse, Wisconsin