40

51

48

9

5

10

5

Ho

dg

kin

's L

ym

ph

om

a -

sta

gin

g

Ho

dg

kin

's L

ym

ph

om

a -

re

sta

gin

g

No

n-H

od

gkin

's L

ym

ph

om

a

Ha

em

ato

log

ica

l M

alig

na

nc

y

Rh

ab

do

myo

sarc

om

a

Ne

uro

bla

sto

ma

Oth

er

Tum

ou

rs

Ne

uro

fib

rom

ato

sis

Typ

e 1

Do

se c

on

sid

era

tio

nT

he E

uro

pean A

ssocia

tion o

f N

ucle

ar

Medic

ine (

EA

NM

) pro

vid

e a

paedia

tric

dose c

alc

ula

tor

for

PE

T im

agin

g in c

hild

ren. A

n e

xam

ple

of

the e

xpecte

d d

oses is d

em

onstr

ate

d in T

able

2.

Doses a

re h

igher

than C

T o

r P

ET

alo

ne,

but th

e a

dditio

nal

info

rmation c

an h

ave s

ignific

ant

impact

on p

atient

managem

ent.

The

dose r

isk-u

tilit

y b

enefit

should

be c

onsid

ere

d o

n a

case

-to-c

ase b

asis

.

CT

dose w

ill r

ely

on local scanner,

scannin

g p

roto

col and p

atient

siz

e.

Paed

iatr

icP

ET

-CT:

a 1

0-y

ear

serv

ice r

evie

w

Dis

cu

ssio

n

Intr

od

ucti

on

The

use o

f F

18

-FD

G P

ET

-CT

is w

ide

ly e

sta

blis

hed in a

dult im

agin

g.

In c

ontr

ast, th

e e

xperi

ence o

f its u

se in th

e p

aed

iatr

ic p

op

ula

tion is

rela

tively

lim

ited

. In

20

14,

a d

edic

ate

d p

aedia

tric

PE

T-C

T g

uid

elin

e

was p

roduced b

y t

he

RC

R.

Prio

r to

this

, vario

us c

linic

al guid

elin

es

exis

ted

at

the

natio

nal and

Euro

pean

le

vel fo

r ad

ults, w

hic

h w

ere

used b

y e

xtr

apo

latio

n in

child

ren

. T

his

le

d to

un

ce

rtain

ty a

nd

a

hete

rogen

eou

s u

se o

f P

ET

-CT

in

this

patient

pop

ula

tion.

We p

rovid

e a

n in

sig

ht in

to t

he s

cope

of

pae

dia

tric

FD

G P

ET

-CT

scans p

erf

orm

ed a

t a

la

rge

tea

ch

ing h

ospital over

a 1

0 y

ear

peri

od.

We a

im t

o h

ighlig

ht curr

ent

RC

R a

nd

Euro

pea

n g

uid

elin

es,

co

nsid

era

tio

ns o

f scan a

cq

uis

itio

n,

inte

rpre

tatio

n p

itfa

lls a

nd

rad

iatio

n d

ose.

Re

fere

nc

es

Sy

ste

mD

iag

no

sis

Gu

ide

lin

es

On

co

log

yH

od

gk

in’s

an

d n

on

-Ho

dg

kin

’s ly

mp

ho

ma

,

eq

uiv

oc

al st

ag

e 4

dis

ea

se o

n o

the

r im

ag

ing

,

extr

a-m

ed

ulla

ry le

uka

em

ia, m

alig

na

nc

y o

f

un

kn

ow

n p

rim

ary

, so

fttiss

ue

sa

rco

ma

, M

IBG

-ve

ne

uro

bla

sto

ma

, g

erm

ce

ll tu

mo

urs

, La

ng

erh

an

s’

ce

ll h

isto

cyto

sis,

re

lap

sed

FD

G +

ve

dis

ea

se.

RC

R 2

016

1

RC

R P

ae

ds

2014

2

EA

NM

2008

3

Ne

uro

log

yFo

ca

l e

pile

psy

. M

alig

na

nt

tra

nsf

orm

atio

n o

f a

ple

xifo

rm o

r su

bc

uta

ne

ou

s n

eu

rofib

rom

a in

ne

uro

fib

rom

ato

sis

1

RC

R 2

016

1

RC

R P

ae

ds

2014

2

EA

NM

2008

3

Infe

ctio

n a

nd

infla

mm

atio

n

Py

rexia

of u

nk

no

wn

orig

in,v

asc

ulit

is, fo

ca

l

infe

ctio

n in

imm

un

oc

om

pro

mis

ed

pa

tie

nts

RC

R 2

016

1

EA

NM

/SN

MM

I

2013

4

Tab

le 1

: S

ele

cte

d i

nd

icati

on

s f

or

the u

se o

f F

DG

PE

T-C

T in

th

e p

aed

iatr

ic p

op

ula

tio

n a

s p

er

gu

idelin

e.

Ind

icati

on

s

in b

old

are

so

me o

f th

e m

ost

freq

uen

tly r

eq

ueste

d a

t o

ur

insti

tuti

on

. F

ull g

uid

elin

es a

vailab

le i

n r

efe

ren

ces.

Me

tho

ds

Retr

osp

ective r

evie

w o

f a

pro

sp

ectively

main

tain

ed

in

stitu

tio

nal P

ET

-

CT

data

ba

se

for

all

sca

ns p

erf

orm

ed in

patie

nts

un

der

the

ag

e o

f 17 a

t

a s

ingle

in

stitu

tio

n. P

atient

de

mogra

phic

s,

clin

ical in

dic

atio

n, acqu

isitio

n

pro

tocol, s

ca

n fin

din

gs, fo

llow

-up a

nd

fin

al outc

om

e w

ere

record

ed.

84

patie

nts

un

derw

ent

15

2 P

ET

-CT

scans o

ver

a 1

0 y

ear

peri

od.

Clin

ica

l dem

and a

pp

ears

to b

e o

n th

e in

cre

ase (

Fig

1).

132

(87%

)

scans w

ere

perf

orm

ed f

or

oncolo

gic

al in

dic

atio

ns. N

on

-oncolo

gic

al

scans w

ere

perf

orm

ed f

or

a v

ari

ety

of in

dic

atio

ns in

clu

din

g infe

ctio

n

and

in

fla

mm

ation,

pyre

xia

of u

nknow

n o

rigin

and e

pile

psy (

Fig

2).

Resu

lts

Use o

f F

DG

PE

T-C

T in p

aedia

tric

s h

as b

een s

low

er

than in a

dults. T

his

may b

e in p

art

be d

ue t

o lack o

f early e

vid

ence

-based g

uid

ance

and c

oncern

over

dose.

Paedia

tric

PE

T-C

T is n

ow

routinely

esta

blis

hed in H

odgkin

’s lym

phom

a w

here

baselin

eand p

ost-

treatm

ent

scans h

ave a

n e

vid

ence-b

ase f

or

PE

T-a

daptive t

hera

py

5.

When t

here

is u

ncert

ain

ty a

bout

dis

tant

dis

ease o

r re

curr

ence o

n

conventional im

agin

g,

PE

T-C

T c

an b

e u

sed t

o c

larify

and p

ote

ntially

alter

patient

treatm

ent options.

Patient

dose r

isk s

hould

be

consid

ere

d o

n a

case-b

y-c

ase b

asis

, as c

an b

e b

ala

nced b

y t

he b

enefit

of

more

accura

te a

ssessm

ent

and p

ote

ntial im

pact

on

managem

ent.

In o

rder

to a

chie

ve h

igh

-qualit

y im

agin

g,

a d

edic

ate

d p

aedia

tric

pro

tocol should

be d

evelo

ped locally

by a

multi-

dis

cip

linary

team

inclu

din

g r

adio

logis

ts,

radio

gra

phers

/technic

ians,

medic

al physic

s,

paedia

tric

oncolo

gy a

nd a

naesth

etics.

Nu

mb

er

of

stu

die

s p

er

ye

ar

20

08

-2017

Cu

rren

t in

dic

ati

on

s f

or

paed

iatr

ic F

DG

PE

T-C

TIn

dic

ati

on

s f

or

PE

T-

CT

perf

orm

ed

at

ou

r

insti

tuti

on

betw

een

2008-2

017

Fig

1: B

rea

kd

ow

n o

f n

um

be

r o

f P

ET-

CT

stu

die

s p

erf

orm

ed

pe

r ye

ar

fro

m 2

00

8-2

017

. *

Va

lue

s u

p

to J

uly

20

17

-p

roje

cte

d n

um

be

r o

f sc

an

s fo

r 2

01

7 in

ye

llow

. Th

e g

en

era

l tr

en

d s

inc

e 2

01

3 h

as

be

en

a s

tea

dy in

cre

ase

in

PET-

CT

de

ma

nd

. † N

o p

ae

dia

tric

sc

an

s w

ere

pe

rfo

rme

d in

Le

ed

s in

20

08

/09

as

a f

ixe

d P

ET-

CT

sca

nn

er

wa

s n

ot

in p

lac

e u

ntil 2

01

0. P

atie

nts

re

ferr

ed

to

Lo

nd

on

.

6

6

8

Pyre

xia

of

Un

kn

ow

n O

rig

in

Ep

ilep

sy

Syst

em

ic/I

nfe

ctive

No

n -

On

co

log

ica

l

On

co

log

ica

l

Inte

rpre

tati

on

pit

falls

Th

e u

tili

ty o

f P

ET

-CT

Fig

3:

CE

CT

neck s

ho

wed

a left

-sid

ed

necro

tic

lym

ph

no

de i

n s

usp

ecte

d l

ym

ph

om

a

recu

rren

ce.

PE

T-C

T (

axia

l fu

sed

at

the s

am

e

level

as C

T)

an

d P

ET

MIP

co

nfi

rm l

eft

sid

ed

recu

rren

ce a

s w

ell a

s o

ccu

lt c

on

trala

tera

l n

od

al

dis

ease.

Th

is f

ind

ing

alt

ere

d p

lan

ned

pati

en

t

man

ag

em

en

t.

Fig

4:

5 y

ear

old

ch

ild

wit

h p

ers

iste

ntl

y r

ais

ed

infl

am

mato

ry m

ark

ers

an

d s

yste

mic

sym

pto

ms

. P

ET

MIP

(left

) an

d f

used

axia

l P

ET

-CT

(ri

gh

t –

top

) d

em

on

str

ate

d

ab

no

rmal

FD

G u

pta

ke i

n t

he r

igh

t th

igh

mass s

usp

icio

us

for

malig

nan

cy.

MR

I o

f ri

gh

t th

igh

(ri

gh

t -

mid

dle

an

d

bo

tto

m)

an

d b

iop

sy c

on

firm

ed

rh

ab

do

myo

sa

rco

ma

.

PE

T-C

T is t

ypic

ally

reserv

ed f

or

prim

ary

sta

gin

g o

f m

alig

nancy a

nd

pro

ble

m s

olv

ing.

Due t

o

hig

h F

DG

upta

ke in a

variety

of

tum

our

types

and b

ein

g a

whole

body

imagin

g t

echniq

ue,

PE

T-

CT

can d

ete

ct

local and

dis

tant

dis

ease. T

his

makes it

ideal fo

r sta

gin

g,

response a

ssessm

ent

and

recurr

ence d

ete

ction

(Fig

3).

It c

an a

lso d

ete

ction o

ccult

inflam

mato

ry o

r m

alig

nant

path

olo

gy w

hen c

linic

al

assessm

ent,

blo

od t

ests

and c

onventional im

agin

g

have n

ot fo

und a

n

underlyin

g c

ause

(Fig

4).

Pitfa

lls in a

dult P

ET

-CT

are

well

docum

ente

d b

ut

there

are

som

e s

pecific

findin

g m

ore

com

monly

encounte

red in

paedia

tric

patients

. P

hysio

logic

al bro

wn

fat activity c

an s

imula

te d

isease o

r

pote

ntially

mask d

isease in n

eck a

nd

media

stinum

(F

ig 5

).

In p

ost-

chem

oth

era

py p

atients

, th

ym

ic

enla

rgem

ent

and incre

ased F

DG

activity

can m

ake r

esponse a

ssessm

ent

difficult,

especia

lly in lym

phom

a p

atients

. T

his

is

term

ed ‘th

ym

ic r

ebound h

yperp

lasia

’ and

can p

ers

ist

up t

o 2

years

follo

win

g

treatm

ent.

It should

not be m

ista

ken f

or

active d

isease a

nd c

an b

e r

ecognis

ed b

y

the t

ypic

al ‘in

vert

ed V

shape’ on c

oro

nal

imagin

g (

Fig

6).

G C

ham

bers

, R

Fro

od, H

Neja

dham

zeeig

ilani, C

Pate

l

Depart

ment

of

Radio

logy

St Jam

es H

ospital, L

eeds T

eachin

g H

ospital T

rust,

UK

We

igh

t(K

g)

10

19

32

55

70

Ap

pro

xim

ate

Ag

e

(ye

ars

)

15

10

15

Ad

ult

FD

G a

dm

inis

tere

d

ac

tiv

ity (

MB

q)

38

65

102

163

196

Eff

ec

tiv

e d

ose

(m

Sv

)3.6

3.3

3.8

4.0

3.7

Tab

le 2

: In

jecte

d a

cti

vit

y a

nd

eff

ecti

ve d

ose f

or

dif

fere

nt

weig

hts

of

paed

iatr

ic p

ati

en

ts a

s d

efi

ned

by

the E

AN

M

05

10

15

20

25

30

35

Number of studies

Ye

ar

In o

rder

to o

ptim

ise s

can a

cquis

itio

n in p

aedia

tric

patients

, som

e m

odific

ation o

f scannin

g

pro

tocol is

required.

Belo

w a

re k

ey c

onsid

era

tions in o

ur

local paedia

tric

pro

tocol:

Gen

era

l an

aesth

eti

c:

<5 y

ears

–m

ost patients

; 6

-9 y

ears

–case b

y c

ase b

asis

; 10+

years

–not ro

utinely

required. T

his

will

require a

ssis

tance f

rom

a r

egula

r paedia

tric

anaesth

etist.

Pro

pan

olo

l u

se:

Patients

10+

years

of

age s

hould

ideally

have p

ropanolo

l pre

medic

ation

(in t

he a

bsence o

f contr

ain

dic

ations)

prior

to the s

tudy t

o s

uppre

ss b

row

n f

at activity.

Local

pro

tocol should

be a

gre

ed w

ith p

aedia

tric

oncolo

gis

ts.

Inje

cte

d a

cti

vit

y:

Based o

n b

odyw

eig

ht

(see d

ose c

onsid

era

tions b

ox)

and a

dju

sting b

ed

positio

n t

imin

g t

o e

nsure

the p

atient

can t

ole

rate

the e

ntire

scan

Oth

er:

The s

can r

oom

can b

e a

n intim

idating p

lace f

or

young c

hild

ren a

nd t

he u

se o

f a p

lay

thera

pis

t should

be c

onsid

ere

d. A

pre

-scan v

isit t

o t

he d

epart

ment

and s

canner

room

can

reduce a

nxie

ty f

or

the c

hild

and p

are

nts

. T

he inje

ction a

nd s

can r

oom

s s

hould

be k

ept

warm

, especia

lly in w

inte

r, in o

rder

to m

inim

ise b

row

n f

at activity.

Op

tim

isin

g s

can

acq

uis

itio

n a

nd

qu

ality

*

1 –

Ro

ya

l Co

lleg

e o

f P

hysi

cia

ns

of

Lon

do

n, R

oya

l Co

lleg

e o

f P

hysi

cia

ns

an

d S

urg

eo

ns

of

Gla

sgo

w, R

oya

l Co

lleg

e o

f P

hysi

cia

ns

of

Ed

inb

urg

h, R

oya

l Co

lleg

e o

f R

ad

iolo

gis

ts,

British

Nu

cle

ar

Me

dic

ine

So

cie

ty, A

dm

inis

tra

tio

n o

f R

ad

ioa

ctiv

e S

ub

sta

nc

es

Ad

vis

ory

Co

mm

itte

e.

Ev

ide

nc

e-b

ase

d in

dic

atio

ns

for

the

use

of

PET-

CT

in t

he

Un

ite

d K

ing

do

m

20

16

. Lo

nd

on

: Th

e R

oya

l Co

lleg

e o

f R

ad

iolo

gis

ts, 2

01

6.

2 –

The

Ro

ya

l Co

lleg

e o

f R

ad

iolo

gis

ts. G

uid

elin

es

for

the

use

of

PET-

CT

in c

hild

ren

. Se

co

nd

Ed

. Lo

nd

on

: Th

e R

oya

l Co

lleg

e o

f R

ad

iolo

gis

ts, 2

01

4.

3 –

Str

au

ss J

, Fra

nzi

us

C,

Plu

ge

r T,

et

al.

Gu

ide

line

s fo

r 1

8f-

FD

G P

ET

an

d P

ET-

CT

ima

gin

g in

pa

ed

iatr

ic o

nc

olo

gy. Eu

r J

Nu

cl M

ed

Mo

l Im

ag

ing

. 2

00

8; 3

5(8

):1

58

1-8

8.

4 –

Jam

ar

F, B

usc

om

be

J,

Ch

iti A

, e

t a

l. EA

NM

/SN

MM

I g

uid

elin

e f

or

18

F-F

DG

use

in

infla

mm

atio

n a

nd

in

fec

tio

n. J

Nu

cl M

ed

. 2

01

3; 5

4(4

):6

47

-58

.5

–C

he

son

B, Fis

he

r R

, B

arr

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†