W A B I P N E W S L E T T E R
P A G E 3
PET-occult LN metastases, and the high number of “normal”
lymph nodes (>2 in a majority of paents – unpublished da-
ta) sampled.
In tension with the desire to complete thorough medias-
nal/hilar LN evaluaon is the need to dene sampling crite-
ria to manage resource ulizaon and prevent procedure
mes extending unreasonably. Certainly, should a novel thin
convex probe videobronchoscope, previously reported in ex
vivo human models to allow assessment of almost all seg-
mental bronchii and even cytologic sampling of subsegmen-
tal LN,[17] become available, it is unlikely to be feasible to
perform as extensive sampling as this instrument will per-
mit. There may be a point where future of EBUS in some
areas may now be to begin more selecve targeng of LN. It
remains to be established exactly what extent of LN sam-
pling should be performed in paents with NSCLC undergo-
ing “systemac” mediasnal evaluaon – should procedur-
alists rounely sample all 5 mediasnal staons or should
systemac evaluaon with EBUS be followed only by limited
sampling with TBNA, perhaps based on probability of meta-
stac involvement (eg. Canada Lymph Node Score[18])?
Alternavely, in paents with cN0-2, perhaps an approach
analogous to surgical R-staging (ensuring at least one
“normal” LN at a higher echelon than the highest patholog-
ic/PET-posive LN is sampled – avoiding R(un)).[19] Equally,
is evaluaon of contralateral hilar LN necessary when the
detecon rate of PET-occult metastases is just 1%?[12] As
an illustraon of this challenge, the number of LN sampled
during “systemac” mediasnal staging varies widely be-
tween reports from just one, to as high as eight.[20]
Beyond opmal pathways for performance of EBUs-TBNA,
the elegance and technical simplicity of the convex probe
scope will also allow expansion of minimally invasive tech-
niques, especially in combinaon with novel technologies/
tools. Already, mediasnal cryobiopsy has been demonstrat-
ed in randomised studies to provide superior diagnosis to
EBUS-TBNA in lymphoma.[21-23] Notably, while some au-
thors have suggested EBUS-cryobiopsy may be more eec-
ve in achieving molecular evaluaon in NSCLC,[23] there
are sucient reports to suggest that obtaining adequate
cellularity [24, 25] and improvements to specimen handling/
processing may achieve the same outcomes. To illustrate
what can be achieved with EBUS-TBNA specimens, one large
mul-centre study reported ability to perform whole ge-
nome sequencing using EBUS specimens in approximately
half of 220 cases.[26] This highlights the importance not just
of connued technical progression, but of ensuring opmal
performance of techniques already well established, as dis-
cussed above.
current standard of care in management of NSCLC.
Is there sll further for EBUS-TBNA to advance?
Looking to the future, advances in EBUS-TBNA are
likely to fall into one of two categories; rstly the
excing idea of incorporaon of novel techniques/
technologies, and ; secondly the less exhilarang
but possibly more impacul advance of more con-
sistent and opmal use of EBUS-TBNA in assessing
paents with NSCLC.
ERS/ESTS as noted above recommend pre-
operave systemac mediasnal nodal staging in
paents with T2/cN1/centrally posioned tumours.
[9] This previously was predicated on the potenal
for upstaging by EBUS-TBNA to N2 disease which
may result in non-surgical management being pre-
ferred. Recent advances in immune checkpoint
inhibitor (ICI) therapy now also emphasize the rou-
ne sampling of hilar LN in addion to mediasnal
staons. Mulple RCTs demonstrate a survival ad-
vantage for paents with Stage IIA-III receiving
neoadjuvant ICI,[11] emphasizing the importance
of thorough evaluaon of hilar (and even intra-
pulmonary where possible) LN. Therefore, as rec-
ommended in the recently published WABIP expert
panel consensus statement on proposed quality
indicators for EBUS,[12] all paents with Stage Ib-
IIIA NSCLC should be considered for systemac
staging with EBUS-TBNA.
The eld of implementaon science exists to ad-
dress the consistent gap between what evidence
suggests is opmal care, and what is rounely per-
formed day-to-day. Reducing variance in care is an
eecve low-cost way to signicantly improve de-
livery of care for our paents. Anecdotally, system-
ac staging is inconsistently performed except in
jurisdicons where it is mandated. Notably, moni-
toring of quality has been demonstrated to im-
prove performance of EBUS and idenfy specic
areas for aenon.[13, 14] This endeavour remains
a key challenge in the future of EBUS-TBNA. In-
creasing the proporon of paents with Stage Ib-
!!!A NSCLC undergoing systemac staging will be a
key challenge in the future of EBUS-TBNA to ensure
consistent opmal care. Future work in prospec-
vely embedding this pracce is required, and may
involve some changes to current pracce. For ex-
ample, synopc procedural reporng is ulized in
endoscopic procedures to ensure opmal quality of
procedures.[15, 16] Synopc reporng was ulised
in the SEISMIC study and may have been a contrib-
ung factor to the signicant rate of detecon of