Reviewer ’s report  
 
Title: Diagnosis of vascular invasion in pancreatic ductal adenocarcinoma using endoscopic 
ultrasound elastography  
 
Version: 0 Date: 16 Feb 2020  
 
Reviewer: Vincenzo Napolitano  
 
Reviewer's report:  
 
The study is remarkable because it is the first report of EUS Elastography for the assessment of 
vascular invasion in PDAC. The proposed criterion to detect vascular involvement by EUS -EG 
seems to be reproducible and objective.  
 
Therefore, it could constitute a substantial improvement for T staging and resectability, 
overcoming limitations of CT, especi ally in difficult cases, with no evident signs of infiltration, 
such as vessel wall irregularity or stenosis. Unfortunately, in the group of subjects included in 
the study, only in a few cases the vessels that have been assessed were those that are crucial  to 
establish resectability, i.e. particularly the  superior mesenteric vein (7 cases) or the superior 
mesenteric artery (1 case). Considering that these vessels  are just the most difficult to image by 
EUS B -mode, it would have been very interesting to te st the reliability of EUS Elastography for 
their assessment. Of course, as the Authors correctly underlined, subjects with suspected 
invasion of the SMA or celiac artery are considered unresectable; this explains why a very small 
number of those vessels ha ve been assessed. Nevertheless, this circumstance influences the 
quality of the results.  
 
It would be useful to indicate which vessels have been assessed in the difficult diagnosis sites 
group and in the 36 subjects who underwent EUS -EG. 
 
A limitation of the  study concerns the heterogeneity of the equipments which have been used. It 
would be opportune to know how many times each of the different ultrasound systems have been 
employed. With regard to the echoendoscopes it would be important to specify the numbe r of 
procedures performed with a linear instrument, a radial instrument or both, and to verify if there 
are any differences in detecting vascular invasion depending on scanning modalities.  
 
Correct spleen vein and spleen artery in table 1.  
 
Are the methods appropriate and well described?  
If not, please specify what is required in your  comments to the authors.  
 
Yes 
 
Does the work include the necessary controls?  
If not, please specify which controls are required in your comments to the authors.  
 
Yes 
 
Are the conclusions drawn adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
 
Yes 
 
Are you able to assess any statistics in the manus cript or would you recommend an 
additional statistical review?  
If an additional statistical review is recommended, please speci fy what aspects require further 
assessment in  your comments to the editors.  
 
I am able to assess the statistics  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Acceptable  
 
Declaration of competing interests  
Please complete a declaration of competing interests, cons idering the following questions:  
 
1.  Have you in the past five years received reimbursements, f ees, funding, or salary 
from an organisation that may in any way gain or lose financial ly from the 
publication of this manuscript, either now or in the future?  
 
2.  Do you hold any stocks or shares in an organisation t hat may in any way gain or 
lose financially from the publication of this manuscript, either now or in the 
future?  
 
3.  Do you hold or are you currently applying for any patents relating to the content 
of the manuscript?  
 
4.  Have you received reimbursements, fees, funding, or salary from an organization 
that holds or has applied for patents relating to the content of the manuscript?  
 
5.  Do you have any other financial competing interests?  
 
6.  Do you have any  non-financial competing interests in relation to this paper?  
 
If you can answer no to all of the above, write 'I declare that I have  no co mpeting interests' 
below. If your reply is yes to any, please give details below.  
 
I declare that I have no competing i nterests  
 
I agree to the open peer review policy of the journal. I understan d that my name will be included 
on my report to the authors and, if the manuscript is accepted f or publication, my named report 
including any attachments I upload will be posted on the website along with the authors'  
responses. I agree for my report to be made available under an Open Access Creative Commons 
CC-BY license ( http://creativecommons.org/licenses/by/4.0/ ). I understand that any comments 
which I do not wish to be included i n my named report can be in cluded as confidential comments 
to the editors, which will not be published.  
 
I agree to the open peer review policy of the journal  
Reviewer ’s report  
 
Title: Diagnosis of vascular invasion in pancreatic ductal adenocarcinoma using endoscopic 
ultrasound elastography  
 
Version: 0 Date: 16 Feb 2020  
 
Reviewer: Vincenzo Napolitano  
 
Reviewer's report:  
 
The study is remarkable because it is the first report of EUS Elastography for the assessment of 
vascular invasion in PDAC. The proposed criterion to detect vascular involvement by EUS -EG 
seems to be reproducible and objective.  
 
Therefore, it could constitute a substantial improvement for T staging and resectability, 
overcoming limitations of CT, especi ally in difficult cases, with no evident signs of infiltration, 
such as vessel wall irregularity or stenosis. Unfortunately, in the group of subjects included in 
the study, only in a few cases the vessels that have been assessed were those that are crucial  to 
establish resectability, i.e. particularly the  superior mesenteric vein (7 cases) or the superior 
mesenteric artery (1 case). Considering that these vessels  are just the most difficult to image by 
EUS B -mode, it would have been very interesting to te st the reliability of EUS Elastography for 
their assessment. Of course, as the Authors correctly underlined, subjects with suspected 
invasion of the SMA or celiac artery are considered unresectable; this explains why a very small 
number of those vessels ha ve been assessed. Nevertheless, this circumstance influences the 
quality of the results.  
 
It would be useful to indicate which vessels have been assessed in the difficult diagnosis sites 
group and in the 36 subjects who underwent EUS -EG. 
 
A limitation of the  study concerns the heterogeneity of the equipments which have been used. It 
would be opportune to know how many times each of the different ultrasound systems have been 
employed. With regard to the echoendoscopes it would be important to specify the numbe r of 
procedures performed with a linear instrument, a radial instrument or both, and to verify if there 
are any differences in detecting vascular invasion depending on scanning modalities.  
 
Correct spleen vein and spleen artery in table 1.  
 
Are the methods appropriate and well described?  
If not, please specify what is required in your  comments to the authors.  
 
Yes 
 
Does the work include the necessary controls?  
If not, please specify which controls are required in your comments to the authors.  
 
Yes 
 
Are the conclusions drawn adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
 
Yes 
 
Are you able to assess any statistics in the manus cript or would you recommend an 
additional statistical review?  
If an additional statistical review is recommended, please speci fy what aspects require further 
assessment in  your comments to the editors.  
 
I am able to assess the statistics  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Acceptable  
 
Declaration of competing interests  
Please complete a declaration of competing interests, cons idering the following questions:  
 
1.  Have you in the past five years received reimbursements, f ees, funding, or salary 
from an organisation that may in any way gain or lose financial ly from the 
publication of this manuscript, either now or in the future?  
 
2.  Do you hold any stocks or shares in an organisation t hat may in any way gain or 
lose financially from the publication of this manuscript, either now or in the 
future?  
 
3.  Do you hold or are you currently applying for any patents relating to the content 
of the manuscript?  
 
4.  Have you received reimbursements, fees, funding, or salary from an organization 
that holds or has applied for patents relating to the content of the manuscript?  
 
5.  Do you have any other financial competing interests?  
 
6.  Do you have any  non-financial competing interests in relation to this paper?  
 
If you can answer no to all of the above, write 'I declare that I have  no co mpeting interests' 
below. If your reply is yes to any, please give details below.  
 
I declare that I have no competing i nterests  
 
I agree to the open peer review policy of the journal. I understan d that my name will be included 
on my report to the authors and, if the manuscript is accepted f or publication, my named report 
including any attachments I upload will be posted on the website along with the authors'  
responses. I agree for my report to be made available under an Open Access Creative Commons 
CC-BY license ( http://creativecommons.org/licenses/by/4.0/ ). I understand that any comments 
which I do not wish to be included i n my named report can be in cluded as confidential comments 
to the editors, which will not be published.  
 
I agree to the open peer review policy of the journal  
Please review this paper.
user
Reviewer ’s report  
 
Title: Diagnosis of vascular invasion in pancreatic ductal adenocarcinoma using endoscopic 
ultrasound elastography  
 
Version: 0 Date: 16 Feb 2020  
 
Reviewer: Vincenzo Napolitano  
 
Reviewer's report:  
 
The study is remarkable because it is the first report of EUS Elastography for the assessment of 
vascular invasion in PDAC. The proposed criterion to detect vascular involvement by EUS -EG 
seems to be reproducible and objective.  
 
Therefore, it could constitute a substantial improvement for T staging and resectability, 
overcoming limitations of CT, especi ally in difficult cases, with no evident signs of infiltration, 
such as vessel wall irregularity or stenosis. Unfortunately, in the group of subjects included in 
the study, only in a few cases the vessels that have been assessed were those that are crucial  to 
establish resectability, i.e. particularly the  superior mesenteric vein (7 cases) or the superior 
mesenteric artery (1 case). Considering that these vessels  are just the most difficult to image by 
EUS B -mode, it would have been very interesting to te st the reliability of EUS Elastography for 
their assessment. Of course, as the Authors correctly underlined, subjects with suspected 
invasion of the SMA or celiac artery are considered unresectable; this explains why a very small 
number of those vessels ha ve been assessed. Nevertheless, this circumstance influences the 
quality of the results.  
 
It would be useful to indicate which vessels have been assessed in the difficult diagnosis sites 
group and in the 36 subjects who underwent EUS -EG. 
 
A limitation of the  study concerns the heterogeneity of the equipments which have been used. It 
would be opportune to know how many times each of the different ultrasound systems have been 
employed. With regard to the echoendoscopes it would be important to specify the numbe r of 
procedures performed with a linear instrument, a radial instrument or both, and to verify if there 
are any differences in detecting vascular invasion depending on scanning modalities.  
 
Correct spleen vein and spleen artery in table 1.  
 
Are the methods appropriate and well described?  
If not, please specify what is required in your  comments to the authors.  
 
Yes 
 
Does the work include the necessary controls?  
If not, please specify which controls are required in your comments to the authors.  
 
Yes 
 
Are the conclusions drawn adequately supported by the data shown?  
If not, please explain in your comments to the authors.  
 
Yes 
 
Are you able to assess any statistics in the manus cript or would you recommend an 
additional statistical review?  
If an additional statistical review is recommended, please speci fy what aspects require further 
assessment in  your comments to the editors.  
 
I am able to assess the statistics  
 
Quality of written English  
Please indicate the quality of language in the manuscript:  
 
Acceptable  
 
Declaration of competing interests  
Please complete a declaration of competing interests, cons idering the following questions:  
 
1.  Have you in the past five years received reimbursements, f ees, funding, or salary 
from an organisation that may in any way gain or lose financial ly from the 
publication of this manuscript, either now or in the future?  
 
2.  Do you hold any stocks or shares in an organisation t hat may in any way gain or 
lose financially from the publication of this manuscript, either now or in the 
future?  
 
3.  Do you hold or are you currently applying for any patents relating to the content 
of the manuscript?  
 
4.  Have you received reimbursements, fees, funding, or salary from an organization 
that holds or has applied for patents relating to the content of the manuscript?  
 
5.  Do you have any other financial competing interests?  
 
6.  Do you have any  non-financial competing interests in relation to this paper?  
 
If you can answer no to all of the above, write 'I declare that I have  no co mpeting interests' 
below. If your reply is yes to any, please give details below.  
 
I declare that I have no competing i nterests  
 
I agree to the open peer review policy of the journal. I understan d that my name will be included 
on my report to the authors and, if the manuscript is accepted f or publication, my named report 
including any attachments I upload will be posted on the website along with the authors'  
responses. I agree for my report to be made available under an Open Access Creative Commons 
CC-BY license ( http://creativecommons.org/licenses/by/4.0/ ). I understand that any comments 
which I do not wish to be included i n my named report can be in cluded as confidential comments 
to the editors, which will not be published.  
 
I agree to the open peer review policy of the journal  
assistant