Site Planning and Radiation
Safety for
the PET Facility
Point of View
Jon A. Anderson
Department of Radiology
The University of Texas Southwestern Medical Center at
Dallas
This presentation addresses practical design issues
for PET and PET/CT facilities that
- are involved in cancer imaging of the whole-body
with 18F FDG,
- use unit doses of FDG obtained from an external
radiopharmacy, and
- use dedicated PET or PET/CT scanners.
Cyclotrons, radiopharmacies, and isotope generators are not considered
except peripherally.
AAPM Annual Meeting, 7/07
J. Anderson
1
PET and PET/CT Imaging
Conventional PET
- uses rotating isotopic sources for
acquiring transmission image
- 70 % E/30% T time split
AAPM Annual Meeting, 7/07
J. Anderson
2
Current PET/CT Implementations
Siemens/CPS Biograph Series
- typically, 15 cm axial FOV
- 2D or 3D acquisitions
- newer crystals allow lower noise,
shorter acquisition times
- uses coupled x-ray CT scanner
to acquire transmission image
for attenuation correction
- provides auto registration of
anatomic CT and functional PET
- faster scans through reduced
transmission image time
AAPM Annual Meeting, 7/07
PET/CT
J. Anderson
3
GE Discovery Series
apologies to any vendor
that was inadvertently
omitted!
AAPM Annual Meeting, 7/07
Philips GEMINI
J. Anderson
4
1
Workflow at the PET Center
(FDG Whole Body Scans)
What Is Different When You Have
PET in Your Practice?
Arrival of patient
1) Requirements for patient handling
during injection and uptake phase
Receive doses
10 min
Position Pt
10-60 min
Scan
Release Pt
* steps with
highest
technologist
exposure
QA Check of Scan
Read study
5
AAPM Annual Meeting, 7/07
J. Anderson
6
PET Facility: University of Texas
Southwestern Medical Center at Dallas
1 Hour Uptake, 30 M inute Scan
16
Radioactive
Materials
This facility needs two uptake areas
Dock
Laundry
J. Anderson
PET Facility Throughput Example:
Scan
Utility
Future Camera
Office 1
Room
Reading
Room
East Corridor
10
Phase
7
Uptake
4
Hot
Toilet
Scanning
Hot Lab
Injection Scan
Room 1
#2
Injection
#1
1
Scan
Room 2
Control
South Corridor
Patient Number
*
*
Print for file and referring; distribute to PACS
Maximum Workload Estimation
8:00
Assay of dose
Have Pt empty bladder
Transport Pt to scanner
3) Combined modality scanners
(PET/CT) require consideration of both
gamma-ray and x-ray hazard
13
*
Uptake of pharmaceutical
30-60 min
2) 511 keV energy
-increases exposure rate from doses,
patients
-greatly increases thickness of required
shielding (hence, use time and distance
when possible)
AAPM Annual Meeting, 7/07
Injection of Pt
Pt instruction and prep
West Corridor
Time of Day
#pts/day = (Twork - Tuptake)/Tscan_rm
AAPM Annual Meeting, 7/07
Break
Room
Office 2
Patients
9:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00
Storage
Office 3
Business
Office
Reception &
Waiting
# uptake areas = Tuptake/Tscan_rm
J. Anderson
7
AAPM Annual Meeting, 7/07
J. Anderson
8
2
Hot Lab Details: Dose Storage Area
Notes:
1) Floor
protection
(containers
weigh 66 lbs)
2) Space needed
depends on how
often deliveries
are made; may
have >100 mCi
here at a time,
even for one
scanner
3) Not much
waste
accumulation
(2 hr half-life)
AAPM Annual Meeting, 7/07
J. Anderson
9
Hot Lab Details
Hot Lab Details: Dose Assay and
Preparation Area
Notes:
1) Calibrator
convenient to
dose storage
2) L Block
close to
calibrator
3) Note use of
special PET
carrier for
syringe
4) Note L
Block: thick
window, 2"
lead, 2" lead
wrap-around
AAPM Annual Meeting, 7/07
J. Anderson
10
Injection Room Details
Notes:
1) Injection room
Hot lab
PET/CT bay
are most likely areas to
need shielding
Notes:
1) All this lead requires solid support -- have a heart-toheart talk with the cabinet maker
2) Counter mount of calibrator decreases tech exposure
3) Extra shielding required on well counter to shield
from sources in scanner, calibration sources, patient in
scanner, etc.
4) Use tungsten syringe shields for dose reduction to
fingers.
AAPM Annual Meeting, 7/07
J. Anderson
11
2) To minimize
anomalous uptake
-minimize external
stimuli
-keep patient quiet and
still on gurney or in
injection chair
3) Need adjacent hot
toilet for patients to use
after uptake period.
AAPM Annual Meeting, 7/07
4) Indirect lighting,curtains, noise control
are desirable
J. Anderson
12
3
PET and PET/CT Imaging Suites
PET/CT
Specifics: Scanner Bay and
Control Rooms Suggestions
Temperature control is vital in both areas -- make sure HVAC
plan is adequate (equipment may shut down automatically
when temperature goes high!); make sure HVAC is zoned so
that uptake areas are separate from scanner/control rooms
Control room (never too many network drops!)
(Console, HIS/RIS, PACS station/DICOM interface)
Conventional PET
Provide for IV contrast injector/ injector control unit
Technologist spends a lot of time here -- evaluate the shielding
to maintain ALARA.
AAPM Annual Meeting, 7/07
J. Anderson
13
Views from Control Room
AAPM Annual Meeting, 7/07
J. Anderson
14
Specifics and Suggestions: Utility
Rooms Required for Some Equipment
Note: orientation of PET/CT
required use of closed circuit
TV to keep patient under
observation.
May be required to hold
- Heat exchangers for cooling the gantry (some gantries
exhaust heat into the scan room instead)
- Uninterruptible power supplies
- Surge suppressors and other power conditioning equipment
One technologist can
monitor both scanners at
the same time.
AAPM Annual Meeting, 7/07
Note: Equipment from some vendors may shut down if
temperature here exceeds specifications! Consider making
your own heat load calculations and asking for extra capacity.
J. Anderson
15
AAPM Annual Meeting, 7/07
J. Anderson
16
4
Site Details: How Much Space is
just examples from
planning guides!
Required for a Scanner? site
check with the vendor
Example
Site Plan
for a
PET/CT
Scanner:
Siemens
Biograph
Vendor
/Equipment
Siemens
Biograph 16
PET/CT
GE
Discovery ST
PET/CT
Philips
Gemini
PET/CT
Scanner
[m] ([ft])
Control
[m] ([ft])
Utility
[m] ([ft])
Total
2
2
[m ] ([ft ])
4.57 x 7.55
(15 x 24.8)
3.20 x 4.00
(10.5 x 13)
3.20 x 2.14
(10.5 x 7)
54
(582)
5.00 x 7.10 3.81 x 2.67 not required
(12.3 x 9.0)
(16.3 x
23.3)
4.8 x 7.9
(16 x 26)
3.6 X 4.8
(12 X 16)
not required
46
(491)
55
(608)
personal advice: get more space to reduce shielding requirements
AAPM Annual Meeting, 7/07
J. Anderson
17
Miscellaneous Personal Advice
on Facility Planning and Start-up
-Keep the hot areas in interior of space, away from
adjacent, uncontrolled occupancies
-Buy enough specialty workstations in original
purchase to allow techs, docs, researchers enough
access (general purpose PACS stations and older NM
workstations are inadequate for evaluating,
processing, or reading these studies)
J. Anderson
19
J. Anderson
18
Radiation Protection Goals: Regulations
Limitations per 10CFR20
Radiation workers
Pregnant worker's fetus
-For multiple scanners, use a common control room
AAPM Annual Meeting, 7/07
AAPM Annual Meeting, 7/07
(in terms of effective dose equivalent)
50 mSv/yr 5000 mrem/yr
5 mSv/9 mo 500 mrem/9 mo
Members of public
1 mSv/yr
in any hour, not to exceed
.02 mSv
(from each licensed operation)
100 mrem/yr
2 mrem
GUIDANCE:
ALARA -- As Low As Reasonably Achievable
AAPM Annual Meeting, 7/07
J. Anderson
20
5
Radiation Protection Goals:
NCRP
The Old Standbys of Radiation
Protection Are Still There: TDS
Recommendations per NCRP 116 (in terms of effective dose)
Radiation workers
50 mSv/yr
5000 mrem/yr
with lifetime limit of
Age x 10 mSv
new facilities designed to limit exposure to "a fraction
of the 10 mSv/yr implied by the lifetime dose limit."
Pregnant worker's fetus
0.5 mSv/mo 50 mrem/mo
Members of public
1 mSv/yr
100 mrem/yr
(All sites or sources! Either limit single-site contribution to 25% of
this, or demonstrate that maximally exposed individual will not
exceed 1 mSv for all contributions.)
AAPM Annual Meeting, 7/07
J. Anderson
21
Shielding and the PET Center
Common Viewpoint: Nuclear medicine departments
don't need shielding
Under older regulatory limits of 5 mSv/yr for members
of the public, little or no additional shielding would be
needed in many cases. This needs to be re-evaluated
under new 1 mSv/yr limits. (5 times less dose allowed)
Another way of putting this: much of the shielding
required in practice is on the order of 2 to 3 half-value
layers (factor of 4-8). Each half value layer is about
1/8” of lead!
AAPM Annual Meeting, 7/07
J. Anderson
23
Time
Distance
Shielding
Shielding is just harder to
come by.
AAPM Annual Meeting, 7/07
J. Anderson
22
Practice of PET Shielding Is Not
Highly Standardized Yet
Excerpts from a web discussion thread on shielding
control areas at PET facilities (from 2000, but the same
discussions are held today):
"...requirements were determined to be 1"
and 1/2" of lead..."
"...we don't have any special shielding..."
"...most do not shield the control room..."
"...this leads to lead thicknesses...of about 2 cm..."
"...we don't have any lead shielding..."
"...we have 2 mm Pb in the walls..."
"... we have ...a lead glass window ... 1/4" of lead
shielding on this wall..."
AAPM Annual Meeting, 7/07
J. Anderson
24
6
Radiation Sources to Include in
the Shielding Plan
AAPM Task Group on PET
Facility Shielding
Mark Madsen
Members:
Jon Anderson
Doug Simpkin
Jeff Kleck
Mike Yester
Richard (Bud) Wendt
John Votaw
Jim Halama
Doses (pre-injection) on hand
Calibration sources for scanner
Patient (in scanner, hot toilet)
J. Anderson
25
Photon (511 keV)
Intensity per Decay
[%]
Positron
Energy
[MeV]
-Ray Dose
µ Sv/hr)/MBq]
[(µ
([(mrem/hr)/mCi])
at 1 meter
11
C 20.3
200
0.961
0.194
(0.717)
13
N 9.97
200
1.19
0.194
(0.717)
15
O 2.03
200
1.72
0.194
(0.717)
194
0.635
0.188
(0.695)
18
F 110.
68
Ge 4.1e5
68
Ga (288 d)
180
82
192
Rb 1.25
AAPM Annual Meeting, 7/07
1.9, 0.8
3.35,2.5
Care must be exercised
to understand the dose
rate constants. These
values, from Unger
and Trubey
(ORNL/RSIC-45) are
given in µSv of deep
dose as defined in
10CFR20. The air
kerma values for 18F at
1 m are
0.179
(0.662)
0.132 (µ
µGy/hr)/MBq
0.210
(0.778)
(0.56 (mR/hr)/mCi)
J. Anderson
CT x-ray source (for PET/CT)
AAPM Annual Meeting, 7/07
J. Anderson
26
The 18F-Injected Patient as a
Source (retained activity)
Dose Rate Constants from Point
Source Positron Emitters
HalfLife
[min]
require CT x-ray
workload factors,
including
additional (nonPET) CT work
TX Sources in scanner (PET)
Report is hoped for by end of 2004. Because this work is
unfinished, today's talk, except when noted, reflects the
author's opinions, not the committee's conclusions.
AAPM Annual Meeting, 7/07
require isotopic
workload
parameters
Patient (post-injection)
Dose Rate from Injected Patient at 1 m
0.600
Dose Rate
[(µ Sv/hr)/MBq]
[(mrem/hr)/mCi]
Chairman:
0.500
0.400
sources of variation:
delay time to measurement,
micturation status, exposure-to-dose
conversion, etc.
0.300
0.200
0.100
0.000
Kearfott 1992
Chisea 1997
Cronin 1999
Benetar 2000
White 2000
Massoth 2003
SI Units
0.075
0.055
0.100
0.150
0.137
0.097
Conventional Units
0.279
0.203
0.370
0.553
0.508
0.359
Source
AAPM 2003 poster
about 20% of dose will be in bladder after 1-2 hours
27
AAPM Annual Meeting, 7/07
J. Anderson
28
7
The 18F-Injected Patient as a Source
(average of different investigators)
µSv/hr)/MBq
Superior 0.075 (µ
0.279 (mrem/hr)/mCi
Isodose Curves from Vendor
all at 1 m from surface of
body, average value from
all applicable reports
Lateral
Anterior
0.104 (µ
µSv/hr)/MBq
0.383 (mrem/hr)/mCi
0.103 (µ
µSv/hr)/MBq
0.383 (mrem/hr)/mCi
not as
anisotropic as is
might seem
0.018 (µ
µSv/hr)/MBq
Inferior 0.065 (mrem/hr)/mCi
AAPM Annual Meeting, 7/07
compare this to
0.014 (µ
µSv/hr)/MBq or
0.05 (mrem/hr)/mCi
99m
for Tc
J. Anderson
with phantom in place
29
Half-Value Layer at 511 keV
Narrow Beam Conditions
[mm]
3
Lead (11.4 g/cm )
3.98
3
34
3
43
Concrete (2.35 g/cm )
Concrete (1.84 g/cm )
with transmission rods
extended
Caveat Shieldor: The phantoms for PET and for CT isodose curves
do not look very much like patients!
Shielding Materials
Material
3
(density in [g/cm ]
with line source in place
AAPM Annual Meeting, 7/07
J. Anderson
30
More Precise Shielding
Calculation Approaches
Correct curves for 511 keV are not in NCRP 49; new NCRP 147 will not
include isotopic information
Alternatives:
- Interpolate between existing curves from NCRP 49
Caveat Shieldor: These are narrow beam values; the observed
attentuation will be less than this in real shielding geometries.
- Use gamma-transport codes (example: Courtney, Health Phys. 81, S24S28 (2001))
Low density concrete is often used for poured-in-place floors over steel
decking, a common construction technique.
- Use buildup or other semi-empirical approach; buildup formalism
µx)e-µ x, where B(µ
µx) is the buildup function
models the intensity as I = IoB(µ
(must use correct factors)
Gypsum wallboard has been investigated (Courtney, Health Phys. 81,
S24-S28 (2001)) but provides little attenuation at reasonable thickness.
- Wait until AAPM Task Group report is issued
AAPM Annual Meeting, 7/07
J. Anderson
31
AAPM Annual Meeting, 7/07
J. Anderson
32
8
Information to Collect for
Shielding Evaluation
A Shielding Paradigm for Mixed
PET/CT Applications (Just a personal opinion)
Uses of adjacent spaces (including above and below) and
occupancy factors for them
# patients/week
isotopes to be used, activity/pt
types of PET studies to be performed (heads, WB, cardiac)
uptake time; scan time
dose delivery schedule; maximum activity on hand
CT technique factors (kVp, mAs/scan [depends of # beds])
# scans per patient
amount of "non-PET" CT workload expected
AAPM Annual Meeting, 7/07
J. Anderson
Identify magnitude and location (x,y) of all sources,
including CT. Integrate over appropriate decay period
that source is in location. Express as dose/wk or dose/hr
at one meter, given workload.
Identify all barriers that will contribute to shielding,
including pigs, shipping containers, etc.
Establish test points (x,y) at perimeter, sensitive
locations. Identify which barriers will shield each point.
33
AAPM Annual Meeting, 7/07
A Shielding Paradigm (cont)
J. Anderson
34
Effects of Adding Corrections to
Dose Calculation
Calculate doses (summed over all sources, including CT)
without attenuation.
Dose at 1 m from 10 mCi F-18Activity
Start adding lead or concrete as necessary to the
barriers, recalculating the doses as you go.
6
Include physical decay
Dose [mrem]
5
Stop when you have met goals (100 mrem/yr, 2
mrem/hr)
Include self-shielding
Include self-shielding, voiding
4
3
2
1
A spreadsheet can do all of this (including corrections for anisotropic sources).
Special purpose programs can be developed to do the same.
Pencil and paper can be used, but it is tedious!
AAPM Annual Meeting, 7/07
J. Anderson
35
0
0
20
40
60
80
100
120
140
Time [min]
AAPM Annual Meeting, 7/07
J. Anderson
36
9
Calculation Grid for PET/CT
Calculations
8
7
9
10
11
12
50
13
14
15
16
17
18
Example Spreadsheet
Verification that no member of the public will
avg per hour
Input Data
Source XRate@1m
1 scan1
3.15
2 scan2
2.6
3 inj 1
3.8
4 inj 2
3.8
5 phan 1
1.1
6 phan 2
1.1
7 lab
54
8 hot_ws
0.13
9 bath
0.45
10 CT
NPETSources
9
19
49
48
66
47
6
20
65
64
23 22
s7 s8 3
s6
s1
s4
45
27
s9
44
s3
43
51
42
41
52
40
39
53
38
54
37
36
35
34
55
60
56
33
32
57
test point
results
28
63
62
61
31
30
58
29
59
PathID
1
2
3
4
AAPM Annual Meeting, 7/07
J. Anderson
Sy
10.49
8.6
7.77
8.81
8.58
9.88
11
11
6.56
9.11
Total Target
mR/wkmR/wk
Loc_ID Occupancy Status Area
1
1 OK control
12.66
2
1 OK control
9.05
3
0.25 OK hot lab
7.61
4
1 OK reading room
3.62
5
1 OK reading room
2.03
6
1 OK reading room
2.44
7
1 OK E wall
1.97
8
1 OK E wall
1.81
9
1 OK E wall
1.97
10
1 OK E wall
1.97
11
1 OK E wall
1.74
12
1 OK E wall
1.70
13
1 OK E wall
1.56
14
1 OK E wall
1.41
15
1 OK E wall
1.28
16
1 OK E wall
1.14
17
1 OK E wall
1.13
26
s2
s10
2
s5
21
24
1
46
Sx
-14.4
-4.43
-17.6
-17.6
-15.9
-8.83
-18.7
-17.8
-22.8
-5.04
source
definitions
5
4
be exposed to more than 100 mrem/yr
37
Where to Put the Lead: Shadow
vs Complete Coverage
XConst
Source Area
3.15 scan1 control
2.60 scan2 control
3.80 inj 1
control
3.80 inj 2
control
100
100
100
100
100
100
2
2
2
2
2
2
2
2
2
2
2
511 Calculation
Buildup Factor Coefficients
Matl
Mu/Rho Rho
Mu
B2
B1
B0
Concrete
0.0877
1.84 0.1614 0.049 0.473 0.994
Lead
0.161
11.34 1.8257 -0.01 0.198 1.05
Lead tranmissions for CT Calc (NCRP49)
d[cm]
B
0
1
Exposure Tolerance:
0.159 2.63E-03
0.3180 5.47E-05
0.4760 1.09E-06
0.6350 1.00E-06
shielding
material
definitions
Tot/Targ
Ratio
0.12664
0.09049
0.0761
0.03618
0.02026
0.02444
0.98403
0.90567
0.98286
0.98251
0.86885
0.85039
0.77788
0.70582
0.64054
0.57104
0.56277
Tx
-10.83
-9.60
-17.84
-12.80
-10.99
-9.60
-20.12
-18.29
-16.46
-14.63
-12.80
-10.97
-9.14
-7.32
-5.49
-3.66
-1.83
Ty
10.06
8.23
11.52
15.55
17.36
15.55
18.29
18.29
18.29
18.29
18.29
18.29
18.29
18.29
18.29
18.29
18.29
Barrier# Thick Orient q[rad] n
[cm]
Loc_IDOccupancy Length
TotReqL,WS
TotL, NS
d(concrete)
d(lead)B1
B2
B3
[rad]
1
1 3.57595 3.021053
1.02
1.12
0 0.16
1
1
1 6.56442 6.058898
0.92
1.02
0 0.163
2
1
1 7.12787 3.468667
0.66
1.23
0 0.84
5
1
1
1 6.86477 3.324703
0.68
1.23
0 0.809
4
1
AAPM Annual Meeting, 7/07
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
8
0
0
0
0
2.54
3.105
2.54
0
0.159
0.159
0.636
0.636
0.636
0.159
0.318
0.636
0
0
0
0
0
0
0
0
0
0
0
90
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1.571
B7
B8
barrier
definitions
B4
J. Anderson
B5
B6
CT Calculation
CT Angle
320 degrees
CT mAs/hr 40000 mAs
1
Comment
1
1
4
4
4
1
2
4
L-Block
PET-Net shipping case + local shielding
1" lead storage case
no barriers counted
n control
s control
s hot lab
s inj 2
s inj 1
n inj area
s scan 2
e hot lab
barriers for each
test point
38
Examples of Shadow Shields
Alternatives:
Complete coverage -- like most x-ray shielding
-contractors are familiar with technique
-facility previously shown had lead thicknesses
of 1.6 mm to 6.3 mm, easily managed
- makes sense for PET/CT where CT must be
shielded
Shadow shielding -- big slabs next to trouble spots
-can reduce overall cost when thick shield needed
- provides flexibility when remodeling old work
AAPM Annual Meeting, 7/07
J. Anderson
39
from JA Anderson, RJ Massoth,
and LL Windedahl, 2003 AAPM
AAPM Annual Meeting, 7/07
J. Anderson
40
10
Calculation Formalism Proposed
by Task Group
AAPM Task Group on PET
Facility Shielding -- In Progress
B, the barrier transmission factor, will be calculated as
1) Evaluating recommended dose rate constants from the
literature for both point sources and the patient as a source.
B=
2) Creating, by Monte Carlo simulation, a set of broad-beam
attenuation graphs/tables for appropriate shielding materials.
Archer equation fits will be given to allow straightforward
calculation of shield thickness from the required barrier
transmission factor
3) Promulgating a set of consistent recommendations on
shielding issues such as those discussed in this talk (the
conclusions may be different, you have heard only the author's
opinion today!)
AAPM Annual Meeting, 7/07
J. Anderson
41
Magnitude of Technologist
Consistent with conventional nuclear medicine
Exposure
practice, most of technologist dose comes from
positioning, transport, and injection.
Dose/Activity Handled
µ Sv/MBq
(mrem/mCi)
Technologist Doses
0.100
average dose/procedure
< 10 µSv (1 mrem)
0.080
0.060
0.040
0.020
0.000
Benetar
Chisea
Chisea
McElroy
UTSW
Average
SI Units
0.018
0.012
0.023
0.019
0.019
0.018
Conventional Units
0.067
0.044
0.085
0.069
0.069
0.067
Reference
AAPM Annual Meeting, 7/07
J. Anderson
43
T * d2 * P
* A0 * t * Rt * N
T = occupancy factor
d = distance to protected point
P = target dose in protected area (per week, hour, etc.)
= dose rate factor
A0 = initial activity contained in patient entering the area at
start of integration time
t = integration time
Rt = reduction factor for integration time
N = number of patients per time period corresponding to P
AAPM Annual Meeting, 7/07
J. Anderson
42
More on Technologist Exposure
1) It is often seen that the technologist dose per mCi handled
drops as a function of experience in the PET clinic.
An update to the previous UTSW data for the same two
technologists as shown on preceding slide shows a normalized
WB dose of 0.011 µSv/MBq (0.041 mrem/mCi), down by 40%
since 2002.
2) Assuming an average dose of 0.07 mrem/mCi injected, 10
pt/day and 10 mCi injected/pt, this would yield a yearly dose of
1750 mrem, within regulation but above most ALARA
investigational limits. Over nine months, it would be 1300
mrem, well above the declared pregnancy limit.
AAPM Annual Meeting, 7/07
J. Anderson
44
11
Operating Suggestions to Minimize
Technologist Dose
Use unit doses.
Short half-life allows release of patient with normal (1015 mCi) amounts of administered FDG activity, even
under conservative assumptions.
Use syringe shields, syringe carriers, carts, etc. to reduce
exposure during dose transport, injection.
Complete patient instruction, interaction before injection.
Minimize time near patient after injection.
Establish IV access with butterfly infusion set before injection.
Use other personnel for patient transport.
J. Anderson
45
Whole Body Scan, HR+ in 2D mode
1.3 rem
(average exposure of
56 mR on axis, free air,
6 bed scan, 8 min/bed,)
Whole Body Scan, Biograph
10 mCi 18F FDG
WB CT scan
(130 kVp, 120 mAs, 5 mm, p = 1.5)
Total
AAPM Annual Meeting, 7/07
J. Anderson
Breast-feeding mothers may expose infants through
proximity rather than through milk until activity has
died away; instruction may be needed (Hicks, J. Nucl.
Med. 42(8), 1238-1242 (2001))
AAPM Annual Meeting, 7/07
J. Anderson
46
Acknowledgements
Effective Dose Comparison:
Conventional PET vs PET/CT
12 mCi 18F FDG
transmission scan
10CFR35.75 and Regulatory Guide 8.39
Release allowed:
unlikely others receive > 5 mSv
Instructions needed: likely to expose others to > 1 mSv
Lay out hot lab to minimize handling time.
AAPM Annual Meeting, 7/07
Release of Radioactive Patients
•
•
•
•
•
•
•
•
Tammy Pritchett, RT, CNMT
Michael Viguet, CNMT
Dana Mathews, MD
Thomas Lane, PhD
Richard Massoth, PhD
Larry Windedahl
Doug Simpkin, PhD
Mark Madsen, PhD
1.1 rem
1.3 rem
2.4 rem
47
AAPM Annual Meeting, 7/07
J. Anderson
48
12
The
End
AAPM Annual Meeting, 7/07
J. Anderson
49
13