Results of a diagnostic imaging audit in a randomised clinical trial in rectal cancer highlight the importance of careful planning and quality control

P a ae al. Insigh s in o Imaging (2023) 14:206
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Resul s o adiagnos ic imaging audi
ina andomised clinical ial in ec al cance
highligh heimpo ance o ca e ul planning
andquali y con ol
Ila ia P a a1,2,3* , Ma ina E iksson4, Jasenko K dzalic5, Elma Mee shoek‑Klein K anenba g2,
Anne G. H. Rood oe s2, Regina Bee s‑Tan6, Co nelis J. H. an de Velde2, Boudewijn an E en7,
Geke A. P. Hospe s8, Beng Glimelius9, Pe J. Nilsson10, Co ie A. M. Ma ijnen11, Koen C. M. J. Pee e s2 and
Lenna K. Blomq is 12
Abs ac
Backg ound Magne ic esonance (MR) imaging is he modali y used o baseline assessmen o locally ad anced
ec al cance (LARC) and es aging a e neoadju an ea men . The o e all audi ed quali y o MR imaging in la ge
mul icen e ials on ec al cance is so a no ou inely epo ed.
Ma e ials andme hods We collec ed MR images ob ained wi hin he Rec al Cance And P e‑ope a i e Induc ion
The apy Followed by Dedica ed Ope a ion (RAPIDO) ial and pe o med an audi o he echnical ea u es o image
acquisi ion. The equi ed MR sequences and slice hickness s a ed in he RAPIDO p o ocol we e used as a e e ence.
Resul s Ou o 920 pa icipan s o he RAPIDO s udy, MR in es iga ions o 668 and 623 pa ien s in he baseline
and es aging se ing, espec i ely, we e collec ed. O hese, 304/668 (45.5%) and 328/623 (52.6%) MR images,
espec i ely, ul illed he echnical quali y c i e ia. The main eason o non‑compliance was exceeding slice hickness
238/668, 35.6% in he baseline se ing and 162/623, 26.0% in he es aging se ing. In 166/668, 24.9% and 168/623,
27.0% MR images in he baseline and es aging se ing, espec i ely, one o mo e o he equi ed pulse sequences
we e missing.
Conclusion Al oge he , 49.0% o he MR images ob ained wi hin he RAPIDO ial ul illed he image acquisi ion
c i e ia equi ed in he s udy p o ocol. High‑quali y MR imaging should be expec ed o he app op ia e ini ial ea ‑
men and esponse e alua ion o pa ien s wi h LARC, and e o s should be made o maximise he quali y o imaging
in clinical ials and in clinical p ac ice.
C i ical ele ance s a emen This audi highligh s he impo ance o adhe ence o MR image acquisi ion c i e ia
o ec al cance , bo h in mul icen e ials and in daily clinical p ac ice. High‑ esolu ion images allow co ec s aging,
ea men s a i ica ion and e alua ion o esponse o neoadju an ea men .
Key poin s
‑ Complying o MR acquisi ion guidelines in mul icen e ials is challenging.
‑ Neglec ion on MR acquisi ion c i e ia leads o poo s aging and ea men .
*Co espondence:
Ila ia P a a
[email p o ec ed]
Full lis o au ho in o ma ion is a ailable a he end o he a icle
Page 2 o 12
P a ae al. Insigh s in o Imaging (2023) 14:206
‑ MR acquisi ion guidelines should be ollowed in ials and clinical p ac ice.
‑ Resea che s should conside manda o y audi s p io o s udy ini ia ion.
Keywo ds Rec al cance , Magne ic esonance imaging, Image acquisi ion p o ocol, Audi
G aphical Abs ac
In oduc ion
Colo ec al cance is he hi d mos common cance
in he wo ld, accoun ing o 10% o all cance s [1]. The
p opo ion o ec al cance a ies depending on he clas-
si ica ion used and usually accoun s o one hi d o all
colo ec al cance s [1, 2]. Accu a e s aging o ec al cance
is impo an because ea men and p ognosis depend
la gely on adiological classi ica ion. His o ically, s aging
o ec al cance was done using only digi al examina ion
and ec oscopy. Cu en ly, magne ic esonance imaging
(MRI) is he echnique o choice o local s aging o ec al
cance , bo h a baseline and as eassessmen a e neoad-
ju an ea men o locally ad anced ec al cance [3, 4].
Accu a e ( e)s aging is o u mos impo ance o assign-
ing pa ien s o he mos app op ia e ea men . Addi-
ionally, MRIs pe o med a e neoadju an ea men
con ibu e o he e e al o pa ien s o non-ope a i e
managemen [5].
Al hough MRI is conside ed he op imal local s aging
echnique o ec al cance , he e a e s ill challenges. The
image quali y and e alua ion a e o pa amoun impo -
ance since consis en high quali y is equi ed o make a
co ec analysis o he umou sp ead [6, 7]. Quali y has
an impac bo h clinically o each pa ien bu also in he
se ing o a clinical ial o ensu e ha pa ien s a e co -
ec ly s a i ied o ea men acco ding o s ipula ed
inclusion c i e ia [6, 7]. The e o e, co ec , s anda dised
MRI p o ocols should be used and ollowed [8].
The Rec al Cance And P e-ope a i e Induc ion The -
apy Followed by Dedica ed Ope a ion (RAPIDO) ial is
an in e na ional andomised con olled phase 3 ial [9].
In he scope o he s udy, pel ic MRI was pe o med a
ini ial s aging and a e neoadju an ea men . Addi ion-
ally, a pel ic MRI was ecommended du ing neo-adju an
ea men . In he s udy p o ocol, he e we e clea quali y
equi emen s e e ing o he MRI acquisi ion p o ocol.
This e ospec i e s udy aimed o e alua e whe he MRIs
pe o med du ing he RAPIDO ial ul illed he quali y
equi emen s ega ding image acquisi ion s a ed in he
s udy p o ocol. Mo eo e , a compa ison wi h he quali y
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P a ae al. Insigh s in o Imaging (2023) 14:206
c i e ia o MRI in o he andomised con olled ials
(RCT) o locally ad anced ec al cance was pe o med.
Ma e ials andme hods
In he RAPIDO ial, pa ien s wi h p ima y locally
ad anced ec al cance de ined by high- isk ea u es on
MRI e alua ion we e andomised be ween wo di e -
en neoadju an ea men egimens ollowed by su ge y
acco ding o he p inciples o o al meso ec al excision
(TME). Pa icipan s alloca ed o he expe imen al g oup
ecei ed sho -cou se adio he apy ollowed by luo o-
u acil- and oxalipla in-based chemo he apy. Pa ien s
alloca ed o he s anda d o ca e g oup ecei ed long
cou se chemo- adio he apy wi h concomi an capeci -
abine. Inclusion c i e ia, neoadju an ea men sched-
ules and endpoin s ha e been epo ed p e iously [9].
MRI p o ocol equi emen s
Each included pa ien unde wen one baseline pel ic
MRI examina ion wi hin 5weeks be o e andomisa ion
and a es aging pel ic MRI examina ion a e neoadju-
an he apy. The ollowing minimal equi emen s o
MRI acquisi ion p o ocols applied o bo h he baseline
and he eassessmen in es iga ions: a ield s eng h o
1.5T o 3T and phased-a ay ecei e coils o pel ic/
body imaging, T2-weigh ed high- esolu ion sequences in
h ee di e en planes (sagi al, axial and co onal oblique
planes) wi h he axial sequence pe pendicula o he
umou axis, wi h maximum 3 mm sec ion hickness
o all sequences (see Addi ional ile1: Supplemen a y
Ma e ials). In case o low umou s, addi ional oblique
sequences bo h pa allel and pe pendicula o he anal
canal we e ecommended. Addi ional sequences, such
as T1-weigh ed and di usion-weigh ed imaging (DWI)
a es aging we e highly ecommended bu no pa o
he obliga o y pulse sequences [10]. These equi emen s
comply wi h he mos ecen in e na ional consensus
guidelines [4, 11, 12].
Quali y con ol
The in en ion o collec and cen ally e iew he adiol-
ogy da a wi h he pu pose o quali y con ol was s a ed in
he o iginal p o ocol o he RAPIDO ial [10], accep ed
by all pa icipan s a he ime o i s pa ien inclusion.
This audi has been pe o med e ospec i ely a e
he conclusion o he main ial. All pa ien s whose MR
images we e e alua ed in he con ex o his audi had
been included in he s udy and ea ed acco ding o he
s udy p o ocol.
Ou o he 920 pa icipan s o he RAPIDO s udy, i
was possible o e ie e MR images o he majo i y o
Du ch and Swedish pa ien s (n = 361 and 332 pa ien s,
espec i ely) and om all pa ien s om Slo enia (n = 36)
o he cu en s udy. Da a we e analysed bo h in he
comple e selec ion o pa ien s and in na ional subg oups.
All collec ed baseline and es aging MRI examina ions
we e assessed o he echnical quali y c i e ia by wo
e iewe s (M.E., I.P.). In pa icula , he p esence o all
equi ed sequences and slice hickness we e assessed
o each in es iga ion. To de ine a common me hod o
e alua ion, an ini ial sample o 40 in es iga ions we e
assessed by bo h e iewe s. The wo k was supe ised by
a adiologis wi h mo e han 30yea s o expe ience in
e iewing pel ic MRI (L.B.). Fo oblique high- esolu ion
T2-weigh ed sequences pe pendicula o he umou , a
slice hickness o up o 3.3mm was ega ded as accep -
able. Mo eo e , a slice hickness o up o 4mm on sagi al
sequences was accep ed, p o ided ha all o he equi ed
sequences we e no hicke han 3mm. The p ocess o
image e ision is p esen ed in Fig.1.
Re iew o simila a icles
Recen ly published RCTs and Eu opean adiology guide-
lines we e e iewed as a compa ison wi h his quali y
audi pe o med on RAPIDO MRI examina ions. A Pub-
Med sea ch using he sea ch e ms “magne ic esonance
imaging” and “ ec al cance ” combined wi h he limi a-
ions o Randomized Con olled T ials ega ding human
subjec s and English language was pe o med and yielded
54 a icles (Janua y 2023). In addi ion, he mos ecen
Eu opean Socie y o Gas oin es inal and Abdominal
Radiology (ESGAR) guidelines we e consul ed as quali a-
i e e e ence [4].
Resul s
The MRI in es iga ions o a o al o 729/920 (79.2%)
pa ien s included in he RAPIDO ial we e conside ed
o his s udy. The MRI examina ions o 668/729 (91.6%)
and 623/729 (85.5%) pa ien s we e a ailable o e iew in
he baseline and es aging se ing, espec i ely (Fig.2).
Mos una ailable scans we e no e ie able om he
pa icipa ing cen es o absen in he sys ems whe e
pa ien s had been ea ed. Some pa ien s we e una ail-
able o adiologic assessmen (died du ing neoadju an
ea men (n = 2), clinical p og ession o disease be o e
he ime o eassessmen (n = 3), con aindica ion o
MRI (n = 2), wi hd ew consen o he s udy (n = 2) and
unknown eason (n = 6)).
Compliance o hep o ocol
In he baseline se ing, 304/668 (45.5%) MRI examina-
ions ul illed he acquisi ion c i e ia s ipula ed in he
p o ocol. The easons o non-compliance o he p o ocol
in he emaining 364 examina ions we e exceeding slice
hickness o one o mo e sequences (90/668, 13.5% and
147/668, 22.0%, espec i ely) o absence o one o mo e
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P a ae al. Insigh s in o Imaging (2023) 14:206
Fig. 1 P ocess o image collec ion and e iew. DICOM = Digi al Imaging and Communica ions in Medicine; MR(I) = Magne ic Resonance (Imaging)
Fig. 2 CONSORT diag am o he popula ion conside ed o his audi . MRI = Magne ic Resonance Imaging; RAPIDO = Rec al Cance
And P e‑ope a i e Induc ion The apy Followed by Dedica ed Ope a ion
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P a ae al. Insigh s in o Imaging (2023) 14:206
o he equi ed sequences (69/668, 10.3% and 97/668,
15.5%, espec i ely). In 40/668 (6.0%), bo h easons
occu ed simul aneously.
In he es aging se ing, 328/623 (52.6%) MRI exami-
na ions complied o he p o ocol. O he 295/623 scans
ha did no ul il he p o ocol, 162 exceeded slice hick-
ness (75/623, 12.0% and 85/623, 13.7% o one o mo e
sequences, espec i ely), and in 27.0% o cases, one o
mo e o he equi ed sequences we e missing (88/623,
14.1% and 80/623, 12.8%, o a single and mul iple
sequence[s], espec i ely). In 5.6%, bo h easons occu ed
simul aneously (35/623) as shown in Table1.
Fo bo h he baseline and he es aging se ing, he
de ails o slice hickness p o ocol de ia ions a e p e-
sen ed in Table2. The numbe o MRIs wi h a 4-mm sag-
i al sequences and 3-mm axial and oblique sequences
ha we e conside ed complian o his analysis we e
90/668 (13.5%) in he baseline se ing and 55/623 (8.8%)
in he es aging se ing. Reasons o no ul ilmen pe
pa icipa ing cen e a e plo ed in Fig.3a and b o he
baseline and he es aging se ings, espec i ely. The ig-
u e shows g oups o cen es wi h a simila le el o (non-)
ul ilmen o p o ocol c i e ia. Reasons o no complying
o he p o ocol o en ecu wi hin each cen e.
Re iew o simila a icles
O he 54 a icles iden i ied du ing he li e a u e sea ch,
20 s udies e e ed o pa ien s wi h locally ad anced ec-
al cance and epo ed he esul s o a andomised clini-
cal ials, including he RAPIDO ial. Toge he wi h he
ESGAR guidelines, hese s udies and he co espond-
ing MRI quali y equi emen s as desc ibed in he main
manusc ip o in he Supplemen a y ma e ial, when
published, a e p esen ed in Table3. Among he selec ed
RCTs, ele en (55%) explici ly e e ed o speci ic MRI
quali y equi emen s. Mos commonly, he ield s eng h
o he machines used o pe o m he MRI in es iga ions,
he employmen o DWI and he exac desc ip ion o he
equi ed sequences we e speci ied as equi emen s. Slice
hickness ≤ 3mm is men ioned in 4/20 s udies (20.0%).
Discussion
This obse a ional s udy p esen s esul s o a quali y
audi o compliance o he MR p o ocol equi emen s in
a la ge andomised mul icen e ial. In he RAPIDO ial
MRI indings we e used as ool o iden i y he eligible
pa ien s o inclusion. Ou o he 729 pa ien s who we e
conside ed o e iew, da a was a ailable o 668 (91.6%)
pa ien s, mos ly e e ing o he baseline se ing. O he
1291 MRIs a ailable o e iew in bo h se ings, only 632
(49.0%) ul illed he image acquisi ion equi emen s con-
ce ning slide hickness and MRI sequences as s ipula ed
in he p o ocol.
Po en ial consequences o non-adhe ence o he p o o-
col include in e p e a ion e o s ha may esul in bo h
o e - and unde s aging [12–15]. Fi s ly, neglec ion o
high- esolu ion T2-weigh ed sequences, images wi h
limi a ions wi h espec o signal o noise [12] o a slice
hickness exceeding he size o lesions [4, 13–16] induce
adiologis s o o e -es ima e he umou ex en [12, 13].
Addi ionally, a poo angula ion as shown in Fig.4a and
b limi s he e alua ion o he muscula is p op ia, i s
ela ion o he meso ec al s uc u es and he e o e he
accu acy o he T-s age assessmen [12]. Mo eo e , high-
esolu ion T2-weigh ed images pe pendicula o he
umou ’s long axis allow a be e de ec ion o ex amu-
al enous in asion, one b oadly ecognised independen
p edic o o local ecu ence, nodal and dis an me as-
ases [17]. Simila ly, meso ec al ascia (MRF) in asion
is a p edic o o local ecu ence [18] and is conside ed
a c i e ium o de ining locally ad anced ec al cance .
While he e is su icien consensus ega ding mac o-
scopic in asion o MRF (i.e. ma gin o 0mm), ag eemen
dec eases when he dis ance be ween he umou and he
MRF is ≤ 1mm (de ined as in ol ed MRF) o 1–2mm
(de ined as h ea ened MRF) e en wi h adequa e MR
images [19]. Low- esolu ion T2-weigh ed MR images
can in e e e wi h he assessmen o MRF in asion. In
Fig.4, MR images ha do no ul il he echnical quali y
c i e ia o hickness and angula ion a e compa ed wi h
a co ec ly pe o med in es iga ion. In he case o he
RAPIDO s udy subop imal quali y o baseline MRI could
po en ially cause inco ec inclusion, while in daily clini-
cal p ac ice, i could lead o inadequa e ea men s a i-
ica ion. Simila ly, inadequa e es aging MRI migh lead
o inaccu a e assessmen o he su gical app oach [16, 20,
21], esul ing in subop imal oncological ou come [11] and
also a po en ial isk o no de ec ing a clinical comple e
esponse. Addi ionally, a highe in e obse e a iabili y
has been epo ed when assessing MR images ha do no
ul il he in e na ional guidelines [13]. The e o e, de ining
and complying o a s anda d MRI p o ocol as ou lined in
in e na ional guidelines is o g ea impo ance.
The esul s o his s udy highligh challenges in mul-
icen e s udies, especially when diagnos ic imaging is
pi o al. Simila ly, his he e ogenei y in p o ocols also
cha ac e ises common clinical p ac ice. In his s udy,
al hough only a p opo ion o all imaging pe o med
was e iewed, MR images o in o al 40 cen es om
h ee coun ies we e e iewed. E en hough a well-
de ined MRI p o ocol was a ailable, only less han hal
o he egis e ed MRI examina ions ul illed he quali y
c i e ia. In pa icula , he e was a end showing ha
o he MRI scans o cen es ha mos ly did no ol-
low he s udy p o ocol he easons o non-compliance
o he MR p o ocols we e consis en , sugges ing ha

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P a ae al. Insigh s in o Imaging (2023) 14:206
Table 1 Numbe o MRI in es iga ions ul illing he p e‑de ined p o ocol c i e ia and he easons o non‑ compliance in bo h he baseline and he p eope a i e se ings.
Numbe s and pe cen ages e e o he whole s udy g oup and o he coun y o each pa ien g oup
a All sequences up o 3.3mm hickness and sagi al sequences only up o 4mm
b Includes cases wi h sagi al sequences only up o 4mm
c No sagi al, axial and co onal oblique sequences a ailable
Baseline N—% Res aging N—%
To al
N = 668 Sweden
N = 302 Ne he lands
N = 331 Slo enia
N = 35 To al
N = 623 Sweden
N = 281 Ne he lands
N = 306 Slo enia
N = 36
Ful illing p o ocol c i e ia 304 45.5% 164 54.3% 116 35.0% 24 68.6% 328 52.6% 165 58.7% 127 41.5% 36 100%
Ful illing o iginal p o ocol 232 34.7% 119 39.4% 91 27.4% 22 62.9% 272 43.7% 143 50.9% 93 30.4% 36 100%
Ful illing adap ed p o ocola72 10.8% 45 14.9% 25 7.6% 2 5.7% 56 9.0% 22 7.8% 34 11.1% 0 0%
No ul illing p o ocol c i e ia 364 54.5% 138 45.7% 215 65% 11 31.4% 295 47.4% 116 41.3% 179 58.5% 0 0%
C i e ia ul ilmen
Slice hickness Ful illingb430 64.4% 223 73.8% 180 54.4% 27 77.1% 461 74.0% 226 80.4% 199 65.0% 36 100%
No ul illing 238 35.6% 78 26.2% 151 45.6% 8 22.9% 162 26.0% 55 19.6% 107 35.0% 0 0%
One sequence 90 13.5% 51 16.9% 34 10.3% 5 14.3% 75 12.0% 39 13.9% 36 11.8% NA
≥ Two sequences 147 22.0% 28 9.3% 116 35.0% 3 8.6% 85 13.7% 16 5.7% 69 22.5% NA
No sequences a ailablec1 0.1% 0 0.0% 1 0.3% 0 0.0% 2 0.3% 0 0.0% 2 0.7% NA
Missing sequences Ful illing 502 75.1% 227 75.2% 243 73.4% 32 91.7% 455 73.0% 206 73.3% 213 69.6% 36 100%
No ul illing 166 24.9% 75 24.8% 88 26.6% 3 8.6% 168 27.0% 75 26.7% 93 30.4% 0 0%
One sequence 69 10.3% 27 8.9% 39 11.8% 3 8.6% 88 14.1% 30 10.7% 58 19.0% NA
≥ Two sequences 97 14.5% 48 15.9% 49 14.8% 0 0% 80 12.8% 45 16.0% 35 14.5% NA
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P a ae al. Insigh s in o Imaging (2023) 14:206
ins i u ions did no adap hei p o ocol bu kep ol-
lowing hei in e nal MR p o ocols (Fig.3a, b). Be o e
s a o he RAPIDO s udy, si es we e in i ed o wo k-
shops, bu a endance was no obliga o y. In u u e
mul icen e s udies, obliga o y wo kshops should
be ca ied ou be o e he ini ia ion o he s udy and
adhe ence o he s udy MR p o ocol o each pa ici-
pa ing cen e should be assessed be o e en y o hei
Table 2 De ails o slice hickness de ia ions
Baseline N—% Res aging N—%
Sagi al
N = 666 Axial oblique
N = 559 Co onal oblique
N = 514 Sagi al
N = 621 Axial oblique
N = 529 Co onal
oblique
N = 472
3–4 mm 220 33.0% 122 21.8% 117 22.8% 143 23.1% 88 16.6% 67 14.2%
5–6 mm 75 11.3% 22 3.9% 13 2.5% 56 9.1% 6 1.1% 4 0.8%
Fig. 3 a, b De ails o easons o non‑ ul ilmen pe pa icipa ing ins i u ion conside ed in his audi (a) in he baseline and (b) es aging se ing.
Reasons o non‑ ul ilmen ecu wi hin mos cen es. Symbol “*” indica es he ollowing: all sequences up o 3.3 mm hickness and sagi al
sequences only up o 4 mm
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P a ae al. Insigh s in o Imaging (2023) 14:206
Table 3 English w i en andomised con olled ials ega ding locally ad anced ec al cance and conside ing MRI as a ( e)s aging echnique
ESGAR Eu opean Socie y o Gas oin es inal and Abdominal Radiology; T, Tesla; MRImagne ic esonance imaging; T1WIT1 weighed imaging
a When umou nea o in ol ing he anal canal
S udy Field s eng h Phased-a ay
ecei e coils T2W
gene al T2 sagi al T2 axial T2
pe pendicula
o long axis
T2 co onal T2 pa allel
o long axis DWI O he desc ip ion
ESGAR guidelines 2018 [4]1.5/3.0 T Yes Yes Yes
≤ 3 mm
Yes
≤ 3 mm
Yes
≤ 3 mm
Yes
b‑ alue ≥ 800
In dis al umou s, a co onal
sequence angula ed pa allel
o he anal canal should be
included o assess he ela ion
be ween umou and anal
sphinc e
1Fe nandez‑Ma os, 2010 [24]1.0/1.5 T Yes
3 mm
Yes Yes
3 mm
Yes
3 mm
Yes
3 mm
Yes
3 mm
NA NA Tu bo spin echo
2Dewdney, EXPERT C, 2012 [25] NA NA NA NA NA NA NA NA NA Thin sliced
MRI (3 mm)
High esolu ion
3Jakobsen, 2012 [26] NA NA NA NA NA NA NA NA NA
4Smi h, 2015 [27]1.5/3.0 T Yes Yes NA NA NA NA NA Yes
5Achiam, 2015 [28]1.5 T NA NA NA NA NA NA NA NA Slice hickness 5 mm
T1WI
Con as enhanced
Bowel ex ension
6Deijen, COLOR III, 2016 [29] NA NA NA NA NA NA NA NA NA
7Glynne‑jones, BACCHUS, 2015 [30] NA NA NA NA NA NA NA NA NA
8Bu bach, RECTAL BOOST, 2015 [31] NA NA Yes NA NA NA NA NA Yes
9Nahas, 2016 [32]1.5/3.0 T NA Yes Yes
3 mm
Yes Yes
3 mm
YesaNA NA
10 Haddad, 2017 [33] NA NA NA NA NA NA NA NA NA
11 Singh, 2017 [34] NA NA NA NA NA NA NA NA NA
12 Lee, 2019 [35] NA NA NA NA NA NA NA NA NA
13 Jameson, SPAR, 2019 [36] NA NA NA NA NA NA NA NA NA
14 Deng, FOWARC, 2019 [37] NA NA NA NA NA NA NA NA NA
15 Nouga e , GRECCAR 4, 2019 [38]1.5/3.0 T Yes NA Yes Yes Yes Yes NA NA
16 Bahadoe , RAPIDO 2021 [9]1.5/3.0 T Yes NA Yes Yes Yes
≤ 3 mm
Yes Yes Op ional T1WI op ional
17 Con oy, PRODIGE 23, 2021 [39] NA NA Yes
3 mm
NA NA NA NA NA NA 3D MRI
18 Akiyoshi, NOMINATE, 2022 [40] NA NA Yes NA NA NA NA NA Yes
19 Chen, 2022 [41]3.0 T NA NA Yes Yes Yes Yes NA Yes Dynamic con as ‑enhanced
T1WI
20 Ominelli, 2022 [42] NA NA NA NA NA NA NA NA NA
Page 9 o 12
P a ae al. Insigh s in o Imaging (2023) 14:206
i s pa ien . Also, egula audi s h oughou he s udy
pe iod should be pe o med ensu ing he quali y o
MRI in all cen es. An example o sys ema ic quali y
assessmen ha is o en pe o med p io o inclusion o
he i s pa ien s in clinical ials in adio he apy is he
so called dummy un. The implemen a ion o quali y
equi emen s is he eby assessed in each pa icipa ing
cen e and majo disc epancies a e sol ed p io o ini-
ia ion [22, 23]. Simila ly, in es iga o s o u u e RCTs
whe e MRI plays a pi o al ole could conside pe o m-
ing manda o y audi s o MR in es iga ions pe o med
in each cen e p io o pa ien s’ andomisa ion. To
add ess his p oblem in common clinical p ac ice, all
cen es should be awa e o and ollow he mos ecen
ESGAR guidelines [4].
Ou o he 20 RCTs used o compa ison, 11 (55%)
epo ed some MRI equi emen s, all ul illing he ec-
ommenda ions o he 2016 ESGAR consensus mee ing
ha was published in 2018 [4]. Howe e , no in o ma ion
was epo ed ega ding how many o he MRI examina-
ions ollowed he de ined p o ocol. To ou knowledge,
he RAPIDO is he i s RCT o pa ien s wi h locally
ad anced ec al cance ha ca ied ou a quali y assess-
men o he imaging pe o med wi hin he s udy.
This s udy has se e al limi a ions. Fi s ly, only 89.5% o
he expec ed MRIs and 69.0% o he examina ions om
he whole s udy we e assessed o echnical ea u es o
image acquisi ion. This was pa ly explained by he sub-
s an ially di e en imaging s o ing and sha ing sys ems
ac oss he pa icipa ing ins i u ions. Fo he u u e, com-
pa ible sha ing sys ems enabling easy image e ie al
du ing and a e ials a e much desi ed. Secondly, he
image quali y was assessed by wo sepa a e e iew-
e s wi h limi ed clinical expe ience in MRI, and his
s udy mainly e iewed he echnical pa ame e s speci-
ied in he MRI iles and explici ly equi ed in he s udy
p o ocol. Consequen ly, o he ele an aspec s ega d-
ing imaging quali y such as ield o iew and oxel size,
Fig. 4 a–d Sagi al and axial (oblique) T2‑weigh ed MR images om wo pa ien s om di e en cen es. Bo h hese in es iga ions we e
pe o med in he baseline se ing; he e o e, di e ences in image quali y a e i espec i e o he e ec s o neoadju an ea men . Tumou bo de s
a e delinea ed wi h con inuous ed lines. Whi e dashed line in a and c = plane o he axial MR image shown in b and d. a, b Bo h he sagi al
and he axial sequences had a slice hickness o 4 mm. In bo h images, he ec al wall is no clea ly de ined. b Axial p ojec ion o he umou .
S uc u es in he meso ec al a a e no clea ly isible. The image o he in asi e on is blu ed (a ows). No sequence pe pendicula o he umou
was ob ained o his pa ien . c, d Bo h he sagi al and he axial oblique sequences had a slice hickness o 3 mm. In bo h cases, he ec al wall
is clea ly de ined, and in asion o he meso ec al a is dis inc . d The in asi e on is indica ed by whi e a ows