ICRP 84 Pregnancy

7/25/2019 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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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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$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

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ICRP 84 Pregnancy

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