ICRP 84 Pregnancy
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Transcript of ICRP 84 Pregnancy
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Pregnancy andPregnancy and
Medical RadiationMedical Radiation
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International Commission
on Radiological Protection
Information abstracted from
ICRPPublication 84
Available at www.icrp.org
Tas Gro!"# R$ %rent& '$ Mettler& L$ (a)ner& C$ Streffer& M$
%err*& S$ +e& T$ ,!sama
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Use and disclaimer
T-is is a Po.erPoint file
It ma* be do.nloaded free of c-ar)e
It is intended for teac-in) and not forcommercial "!r"oses
T-is slide set is intended to be !sed .it-t-e com"lete te/t "rovided in ICRPPublication 84
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Contents
Introd!ction
'etal radiation riss
Informed consent& notices& "re)nanc*
determination
'etal doses from "roced!res
Pre)nant .orers
Researc- involvin) radiation d!rin) "re)nanc*
Iss!res re)ardin) termination of "re)nanc*
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Introduction
T-o!sands of "re)nant .omen are
e/"osed to ionisin) radiation eac- *ear
Lac of no.led)e is res"onsible for )reat
an/iet* and "robabl* !nnecessar*
termination of "re)nancies
'or most "atients& radiation e/"os!re ismedicall* a""ro"riate and t-e radiation
ris to t-e foet!s is minimal
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Example: justified use of CTPregnant female, was in motor vehicle accident
'etal
s!ll
ribs%lood
o!tside
!ter!s
Fetal dose 20 mGy
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3 minute CT exam and taken to the
operating room. She and the child survived
Free lood
!idney torno"" aorta no contrast in it Splenic laceration
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Fetal radiation risk
T-ere are radiation0related riskst-ro!)-o!t
"re)nanc* t-at are related to the stage o"
pregnancy and asored dose
Radiation riss are most si)nificant d!rin)
or)ano)enesis and in t-e earl* fetal "eriod&
some.-at less in t-e 1nd trimester& and least
in t-e 2rd trimester
Less Least
Most
ris
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Radiationinduced malformations
Malformations -ave a threshold o" %00&200 mGy
or higher and are t*"icall* associated .it- central
nervo!s s*stem "roblems
'etal doses of 344 mG* are not reac-ed even .it-2 "elvic CT scans or 14 conventional dia)nostic /0
ra* e/aminations
T-ese levels canbe reac-ed .it- fl!orosco"icall*)!ided interventional "roced!res of t-e "elvis and
.it- radiot-era"*
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Central ner!ous system effects
D!rin) 5016 .ees "ost0conce"tion t-e CNS is
"artic!larl* sensitive to radiation
'etal doses in e/cess of 344 mG* can res!lt insome red!ction of I7 8intelli)ence 9!otient:
'etal doses in t-e ran)e of 3444 mG* can res!lt
in severe mental retardation and microce"-al*&"artic!larl* d!rin) 5036 .ees and to a lesser
e/tent at 3;016 .ees
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'eterotopic gray matter #arrows$ near the ventricles in
a mentally retarded individual occurring as a result o"
high dose in&utero radiation exposure
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Fre(uency o" microcephaly as a "unction o" dose and
gestational age occurring as a result o" in&utero
exposure in atomic om survivors #)iller %*+,$
Dose8cG*:
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"eukaemia and cancer#
Radiation -as been s-o.n to increase t-e
ris for le!aemia and man* t*"es of
cancer in ad!lts and c-ildren
T-ro!)-o!t most of "re)nanc*& t-e
embr*o
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"eukaemia and cancer (contd)
T-e relative ris ma* be as -i)- as 3$=
8=4> increase over normal incidence: d!e
to a fetal dose of 34 mG*
'or an individ!al e/"osed in !tero to 34
mG*& t-e absol!te ris of cancer at a)es 40
36 is abo!t 3 e/cess cancer deat- "er
3&?44
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Pro$a$ility of $earing %ealt%y c%ildren
as a function of radiation dose
Dose to conce"t!s8mG*: above
nat!ral bac)ro!nd
Probabilit* of nomalformation
Probabilit* of nocancer 8403@ *ears:
0 *+ **.+
% *+ **.+
- *+ **.+
%0 *+ **., -0 *+ **.
%00 *+ **.%
/%00 ossile1 see text 'igher
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Preconception irradiation
Pre0conce"tion irradiation of eit-er "arents
)onads -as notbeen s-o.n to res!lt in
increased ris of cancer or malformations in
c-ildren
T-is statement is from com"re-ensive
st!dies of atomic bomb s!rvivors as .ell asst!dies of "atients .-o -ad been treated
.it- radiot-era"* .-en t-e* .ere c-ildren
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Informed consent and understanding
T-e "re)nant "atient or .orer -as a ri)-t to no.t-e ma)nit!de and t*"e of "otential radiationeffects t-at mi)-t res!lt from in0!tero e/"os!re
Comm!nication s-o!ld be related to t-e level ofris$ Comm!nication t-at ris is ne)li)ible isade9!ate for ver* lo. dose "roced!res 8B3 mG* tot-e fet!s:
If fetal doses are above 3 mG*& a more detailede/"lanation s-o!ld be )iven
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Exposure of pregnant patients
In some circ!mstances& t-e e/"os!re isina""ro"riate and t-e !nborn c-ild ma* be atincreased ris of -arm to -ealt-
Prenatal doses from most "ro"erl* "erformeddiagnostic"roced!res "resent nomeas!rabl*increased ris of "renatal deat-& malformation& ormental im"airment
'igherdosess!c- as t-ose from t-era"e!tic"roced!res can result in signi"icant "etal harm
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Medical radiation procedures
All medical "ractices 8occ!"ational and "atient0
related: s-o!ld be !stified 8more benefit t-an ris:
Medical e/"os!res s-o!ld be !stified for eac-
"atient before t-e* are "erformed
After it is decided to do a medical radiation
"roced!re& t-e fetal radiation dose s-o!ld be
red!ced .-ile still obtainin) t-e re9!ired
dia)nostic information
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E!aluation of potentially
pregnant patients
In females of c-ild0bearin) a)e& an attem"t
s-o!ld be made to determine .-o is&
or co!ld be& "re)nant&
"rior to radiation e/"os!re
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&otices
A missed "eriod in a re)!larl* menstr!atin)
.oman s-o!ld be considered d!e to "re)nanc*&
!ntil "roven ot-er.ise
Notices re)ardin) "re)nanc* s-o!ld be "osted
in "atient .aitin) areas& s!c- as" it is possile that you might e pregnant1
noti"y the physician or other sta"" e"ore your x&ray examination1 treatment1 or e"ore eing
inected with a radioactive material
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'pproximate fetal doses from
con!entional xray examinationsData from the UK, 1998
DoseE/amination
Mean 8mG*: Ma/im!m 8mG*:
Abdomen %. .2
C-est 40.0% 40.0%
Intraveno!s !ro0
)ram l!mbar s"ine
%.+ %0
Pelvis %.%
S!llt-oracic s"ine
40.0% 40.0%
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'pproximate fetal doses from fluoroscopic
and computed tomograp%y procedures
Data from the UK, 1998
DoseE/amination
Mean 8mG*: Ma/im!m 8mG*:
%ari!m meal 8GI: %.% -.5
%ari!m enema ,.5 2
+ead CT 40.00- 40.00-
C-est CT 0.0, %.0
Abdomen CT 5.0 *
Pelvis CT 2- 50
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(ig%er dose procedures
Radiation t-era"* and interventionalfl!orosco"icall*0)!ided "roced!res ma*)ive fetal doses in t-e ran)e of 340344
mG* or more de"endin) on t-e s"ecificsof t-e "roced!re
After s!c- -i)-er dose medical "roced!res
-ave been "erformed on "re)nant "atients&fetal dose and "otential fetal ris s-o!ld beestimated b* a no.led)eable "erson
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&uclear medicine and
pregnant patients#
Most dia)nostic "roced!res are done .it- s-ort0
lived radion!clides 8s!c- as tec-neti!m0@@m: t-at
do not ca!se lar)e fetal doses
Often& fetal dose can be red!ced t-ro!)- maternal
-*dration and enco!ra)in) voidin) of !rine
Some radion!clides do cross t-e "lacenta and can"ose fetal riss 8s!c- as iodine0323:
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&uclear medicine and
pregnant patient (contd)
T-e fetal t-*roid acc!m!lates iodine after abo!t 34.ees )estational a)e
+i)- fetal t-*roid doses from radioiodine canres!lt in "ermanent -*"ot-*roidism
If "re)nanc* is discovered .it-in 31 - of radio0iodine administration& "rom"t oral administrationof stable "otassi!m iodine 8;40324 m): to t-emot-er can red!ce fetal t-*roid dose$ T-is ma*need to be re"eated several times
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'pproximate )%ole $ody fetal dose *m+y,
from common nuclear medicine procedures
Proced!re Activit* 8M%9:Earl*
"re)nanc*@ mont-s
Tc0@@m
%one scan
L!n) scan
Liver colloid scan T-*roid scan
Renal DTPA Red blood cell
+-0
20
30000
300
*30
.+
0.*
0.,.
*.0
,.0
%.5
0.*
%.%3.+
3.-
2.-
I0312 t-*roid !"tae 30 0., 0.3
I0323 t-*roid !"tae 0.-- 0.0 0.%-
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&uclear medicine and
$reast feeding
A n!mber of radion!clides are e/creted in breast
mil$ It is recommended t-at breast feedin) is
s!s"ended as follo.s#
F Com"letel* after 323I t-era"*
F 2 .ees after 323I& 312I& ;?Ga& 11Na& and 134Tl
F 31 - after323
I -i""!rate and all@@m
Tc com"o!ndse/ce"t as belo.
F = - after @@mTc red cells& DTPA& and "-os"-onates
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Researc% on pregnant patients
Researc- involvin)
radiation e/"os!reof "re)nant "atients
s-o!ld be
disco!ra)ed
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Radiation exposure of
pregnant )orkers
Pre)nant medical radiation .orers maywork in a radiation environmentas lon)as t-ere is reasonable ass!rance t-at t-efetal dose can be e"t belo. 3 mG*d!rin) t-e "re)nanc*
3 mG* is a""ro/imatel* t-e dose t-at all"ersons receive ann!all* from "enetratin)nat!ral bac)ro!nd radiation
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Termination of pregnancy#
+i)- fetal doses 834403444 mG*: d!rin)late "re)nanc* are not liel* to res!lt inmalformations or birt- defects since all
t-e or)ans -ave been formed
A fetal dose of 344 mG* -as a smallindivid!al ris of radiation0ind!ced
cancer$ T-ere is over a @@> c-ance t-att-e e/"osed fet!s .ill 67Tdevelo"c-ild-ood cancer or le!aemia
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Termination of pregnancy (contd)
Termination of "re)nanc* at fetal doses of less t-an
344 mG* is 67T!stified based !"on radiation
ris
At fetal doses in e/cess of 644 mG*& t-ere can be
si)nificant fetal dama)e& t-e ma)nit!de and t*"e of
.-ic- is a f!nction of dose and sta)e of "re)nanc*
At fetal doses bet.een 344 and 644 mG*& decisions
s-o!ld be based !"on individ!al circ!mstances
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Risks in a pregnant population
notexposed to radiation
Riss#
0 S"ontaneo!s abortion 36>0 Incidence of )enetic abnormalities =034>
0 Intra!terine )ro.t- retardation =>
0 Incidence of maor malformation 10=>
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-e$ sites for additional information
on radiation sources and effects
E!ro"ean Commission8radiolo)ical "rotection "a)es:#europa.eu.int8comm8environment8radprot
International Atomic Ener)* A)enc*# www.iaea.org
International Commission on Radiolo)ical Protection#www.icrp.org
nited Nations Scientific Committee on t-e Effects ofAtomic Radiation#
www.unscear.org(orld +ealt- Or)aniHation# www.who.int