Transcript 137Cs Blood Irradiator - Brigham and Women's Hospital

Radiation protection review for credentialed
fluoroscopy operators at BWH
AY 2012-2013
Dept. of Health Physics and Radiopharmacology
Brigham and Women’s Hospital
Radiation protection review for
credentialed fluoroscopy operators
Why is there a recertification requirement?
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Recent JCAHO and FDA initiatives to reduce patient
radiation dose associated with fluoroscopy, CT, and
nuclear medicine procedures
Updated Massachusetts regulations
To review safe practices of fluoroscopy; and recent
trends in BWH radiation dosimetry
Who provides fluoroscopy oversight?
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Government
- US FDA
- Massachusetts Dept. of Public Health: inspects and
enforces regulations in Massachusetts
Accreditation organizations
- JCAHO, ACR, CMS
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BWH Radiation Safety Committee
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Medical Directors-Radiology, Cardiology, Endoscopy, etc.
Radiation protection regulations
Code of Massachusetts Regulations (CMR)
105 CMR 120: Regulations for the Control of Radiation
120.400: X-RAYS IN THE HEALING ARTS
120.405: Fluoroscopy (updated, March 2012)
All available on-line at the Mass. DPH website
Radiation protection regulations
Who can actually operate fluoroscopic
equipment?
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Board-certified radiologists
Mass. licensed physicians who have undergone fluoroscopy
safety training/credentialing
Mass.-licensed radiologic technologists trained in the safe
use of fluoroscopic x-ray systems
Radiation protection regulations
As of March 2012:
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*
Licensed physician assistants and nurse practitioners who
have met the fluoroscopy safety training requirements and
are supervised by licensed physicians whom have met
fluoroscopy safety training and continuing education
requirements*
not yet formalized by BWH Radiation Safety Committee
Fluoroscopy credentialing @ BWH
Since 1990:
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All new fellows, residents, and attending physicians
undergo a training course with take-home reading
materials, exam, and fluoroscopy competency
assessment.
Upon successful completion, are issued a certificate and
entered into BICS as holding Fluoroscopy privileges
Ad hoc retraining/radiation safety in-services presented
Fluoroscopy credentialing @ BWH
As of 2008 (non-radiologist physicians):
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BICS Fluoroscopy privileges will expire annually
Recertification takes place by viewing on-line study
materials and returning quiz to Health Physics
Ad hoc retraining/radiation safety in-services presented
Recredentialing process @ for BWH
Fluoroscopy operators
Process
1.
MD participant receives notification from Health
Physics that fluoroscopy credential will be expiring
2.
Participant reviews slide show. Contacts RSO with any
questions
3.
Participant completes and returns quiz
4.
BWH Fluoroscopy credentials renewed for the next 12
months
Fluoroscopy: safety concerns?
Stochastic risks
non-threshold
probabilistic
Lead to:
genetic mutation
genomic instability
radiogenic cancer
Deterministic effects
threshold-related
worsen with dose
Lead to:
skin damage
adverse birth
outcomes
Indeterminate risks
changing dose
thresholds
Lead to:
lens opacities
cataract formation
What if the patient is pregnant?
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Consult Pregnancy Policy of the proposed imaging service
Consider alternative imaging procedures (Ultrasound, MRI)
Consider limiting projections, exposure times, cine runs
(in consultation with Radiology or attending cardiologist)
With technical staff, apply additional Pb shielding if possible
See also:
A Health Care Personnel Guide For Assessing Radiation Risk And
Selecting Imaging Procedures In Pregnant Women
http://brighamrad.harvard.edu/education/fetaldose/
What if the fluoroscopist is pregnant?
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Consult Pregnancy Policy of the proposed imaging service
Suggest (i.e., not mandatory) confidentially declaring
pregnancy status to Health Physics Department which then
initiates:
1. Joint review of dosimetry history
2. Joint review of regulations and dose limits
3. Determination if workload or lab environment needs to be
modified during pregnancy
4. Issuance of additional fetal radiation dosimeters
5. Receipt of regular dose surveillance reports.
Fluoroscopy; patient dose-limiting
protocols
Whenever and wherever possible:
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Maintain adequate x-ray source-skin distance
Keep image intensifier as close as possible to patient
Apply positive beam limitation (collimators)
Limit magnification and beam-time
Note: these measures also reduce staff dose
105 CMR 120.405 Summary of changes, as of
March 2012 (fluoroscopy dose reporting)
Each facility performing traditional fluoroscopy or
interventional CT shall:
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conduct patient dose evaluation for any procedure that has a
reasonable probability of resulting in a deterministic injury
have patient dose monitoring procedures in place.
document in the patient’s medical record an estimate of the
absorbed dose to the skin.
Fluoroscopy dose reporting
105 CMR 120.405 Summary of changes, as of
March 2012
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Any cumulative absorbed dose to the skin equal to or greater
than 2.0 Gy (200 rads) shall be noted in the patient’s medical
record and reviewed by the Radiation Safety Committee.
Each facility shall maintain a record for five years of the
cumulative fluoroscopic exposure time used and the number of
spot films for each examination. This record shall indicate
patient identification, type of examination, date of
examination, and operator’s name.
Sample, Dose tracking database from CDIC
Date
MRN
Procedure
Rm
Cor. Intervention
Fluoro
MD
Ref’’g.
MD
Fl. Ti.
(min.)
DAP
(Gycm2)
Cumul
Dose
(mGy)
20
174
1209
LHC
12
27
200
1389
LHC w/ stent
10
74
631
4382
RHC/LHC
12
14
247
1715
LAD Intervention
10
43
242
1681
RHC/LHC
12
14
247
1715
RHC/LHC
10
28
182
1264
Cardiac stent
12
28
200
1389
Left Heart Cath
11
32
234
1625
LCx stent and IVUS
12
48
391
2715
RT notes dose
cumulative doses
> 2 Gy tracked by RSO
Current BWH
dose tracking
scheme
RSO reports to RSC
If cumulative doses > 5 Gy, RSC
prompts fluoroscopist follow-up
Fluoroscopist
contacts referring MD
RSC documents
dose/follow-up
referring MD
follows patient
Occupational dose: staff and trainees
working with ionizing radiation are issued
monthly radiation dosimeters. Options include:
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a single collar badge, with red
icon (worn above Pb)
a single whole body badge,
with black icon (worn below
Pb apron)
- both badges, if you regularly
operate the fluoroscope
during interventional studies.
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a fetal dose monitor, if
pregnancy declared
Radiation – dose limits for staff
Maximum permissible dose (MPD)
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Whole body, deep dose equivalent
(DDE) = 5,000 mrem/yr (= 50 mSv)
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lens = 15,000 mrem/yr (= 150 mSv)
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shallow/extremities = 50,000 mrem/yr (= 500 mSv)
Note: Keep in mind that annual per capita dose from natural
sources of radiation (background) = ~311 mrem
(3.1 mSv) in U.S.
Radiation – dose limits for staff
If declared pregnant worker, fetal dose limits are:
= 500 mrem/gestational period (= 5.0 mSv)
= not to exceed 50 mrem/month (= 0.5 mSv)
Occupational radiation dose trends
# of participants
2011 BWH Deep dose equivalent (mrem)
N = 1873
1000
800
600
= bgd
400
200
0
Series1
not used
<1.0
1-49
50-99
237
944
570
47
100-199 200 -299 300 -499 500 -999 1000 35
16
13
9
2
Annual dose
Note, N = 1873 badged - 237 unknown results = 1636
98.5 % (1612/1636) < “bgd”
99 % (1625//1636) < 10% of maximum permissible dose
2000+
2011 BWH Interventional Cardiology DDE (mrem)
= 192
BWH OccupationalNExposures
45
# of staff
30
15
0
not
used
<1.0
mrem
1-49
50-99
100199
200 299
300 499
CDIC
6
15
40
8
7
3
6
4
EP Lab
7
11
35
8
3
1
1
1
16
3
10
1
3
1
CV Fellow s
annual mrem
EP LAB
98.5% of badged staff received < 10% MPD
97% of badged staff received < annual bgd. value
unknown dose for 10% (7/67) of staff
CATH LAB
93% of badged staff received < 10% MPD
87% of badged staff received < annual bgd. value
unknown dose for 7% (6/91) of staff
500 - 1000 2000+
999
1999
2
Radiation safety maxims for staff
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Decrease time around source
(if possible, move to shielded area for cine runs)
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Increase distance from source
(inverse square relationship)
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Use appropriate shielding/PPE
(0.5 mm Pb equivalent aprons and thyroid collars)
Intensity of the radiation dramatically drops off with distance,
due to the inverse square law:
Exposure rate @ 0.5 m = 100 mR/hr
What is the exposure rate @ 1.5 m
Original intensity
New intensity
= (New distance)2
(Old distance)2
(100 mR/hr)/( ? mR/hr) = (1.5 m)2 /(0.5 m)2
100/x = 2.25/0.25
100/x = 9.0
100 =
9x
x = 100/9
11.1 mR/hr @ 1.5 m
Personal shielding requirements
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Mass. regulations require hospitals to provide sufficient
number and availability of protective lead aprons
BWH Radiology Policy requires use of lead aprons, thyroid
shields, and gloves (as necessary)
Thickness should be at least equal to 0.5 mm Pb equivalent
Pb eyeglasses recommended for many procedures
Radiation Safety Liaisons have been established
for each area to assist you with badges, lead
PPE, etc.
CDIC = Kelley Grassi, RT
EP Lab = Jim McConville, RT, CNMT, Jack West, RT
Endoscopy = Sandra Cialfi, RN
Pain Management = Diane Palombi, RN
Interventional Radiology = Carol Upson, RT, Patrice Embree, RT
Diagnostic (L1) Radiology = Charles David Healy, RT
Emergency Dept. = Angela McLaughlin, RT
Nuclear Medicine/AMIGO = Victor Gerbaudo, PhD
O.R. Nursing = Susan Lovell, RN
O.R. Radiology equipment = Tiffany King, RT
BWH Radiation Safety Contacts
Health Physics
Main # = 617 732 6056; fax# = 617 566 9574
Director & Radiation Safety Officer
Christopher Martel, MS, CHP = 617 732 6057
Dosimeters
Erin Poitras, MS = 617 525 7042
IRB, Training
A. Robert Schleipman, RT, CNMT, MSc = 617 732 5963
Emergency on-call pager = 33330
Patient dose calculations, equipment testing, training
Richard Nawfel, MS
Medical Physics, Radiology = 617 732 7201