the potential benefits for clinical pathology of adopting well - designed digital technologies have been solidly established .
essentially , there are strong arguments pointing to improved patient care and more efficient care pathways in the digital era . the reality , however , often is that the path toward realizing this potential is not straightforward .
the clinical adoption is multi - faceted and for each domain , customized solutions may be required .
there are many efforts around the world aiming to pave the way for digital pathology into routine clinical use , and a particular concentration of development work is happening in the nordic countries ( sweden , denmark , norway , finland , and iceland ) .
for example , full histology scanning and extensive digital primary review are a reality since several years in the hospitals of linkping and kalmar .
recently , gvle hospital started a digital review for parts of the clinical routine , and concrete implementation plans are being carried out in many more institutions .
the nordic symposium on digital pathology ( ndp ) was created in 2013 to promote global exchange of state - of - the - art knowledge , taking advantage of this nordic digital greenhouse .
the specific focus of ndp is advancing toward the clinical adoption of whole - slide imaging ( wsi ) and other digital technologies in pathology .
in particular , a founding principle is the insight that effective progress requires strong collaboration among health care , industry , and academia , and ndp is designed to be a forum where professionals from all these domains can meet .
this third installment of ndp marks a continued evolution from the two previous events in 2013 and 2014 , in terms of participant numbers ( 190 compared to 125 and 144 , respectively ) and depth of issues discussed .
below we provide a summary of ndp 2015 , in the form of a meeting overview , results from the symposium 's validation workshop , speaker contributions , and finally brief conclusions .
a total of 190 attendees gathered , of which 43% listed health care as the primary affiliation , 40% industry , and 16% academia .
the health care representatives were dominated by pathologists , but also managers , laboratory technologists , and it staff were in significant numbers .
the participants represented 15 different countries with the nordic attendees making up the majority ( 82% ) , but less so than in the 2014 symposium ( 87% ) . invited talks
constituted the backbone of the program , together with a collaborative workshop on validation aspects of digital pathology .
the contents of these sessions will be outlined in the sections below . in the science and innovation session ,
this resulted in three jpi papers published alongside this editorial :  consultation of urological specimens using real - time digital microscopy : optimizing the workflow for referred cancer patients  ( henrik holten - rossing et al . ) ,  improving the creation and reporting of structured findings during digital pathology review 
( ida cervin et al . ) , and  feature - based analysis of mouse prostatic intraepithelial neoplasia in histological tissue sections  ( pekka ruusuvuori et al . ) .
in addition , the ndp included an industrial exhibition consisting of 13 vendors , showing a wide range of products and services related to digital pathology operations .
figure 1 shows a snapshot from the symposium , and the program details are available at the ndp website www.ndp2015.se . the nordic symposium on digital pathology 2015 audience gathered for the keynote presentation of prof paul j. van diest a key part of the ndp program was the workshop discussing validation of digital pathology .
the workshop was organized as an open floor discussion with broad participation from the attendees . as an introduction
, a systematic review of previous digital pathology validation research was presented by bethany williams , leeds university . moreover ,
a survey among the health care attendees themselves , distributed in advance of the symposium , served as fuel for debate .
it is important to acknowledge that the survey respondents represent a biased selection among the pathology community .
since only ndp participants were asked , this means that respondents are likely to be among the most positive to digital pathology and also among the most experienced .
there is also a strong geographical dominance from the nordics and , in particular , sweden . of 83
it is likely that the pathologist dominance was even higher for some questions that require deep knowledge of clinical practice .
role distribution of survey respondents the survey first asked :  today , to what degree do you use digital images of histology slides in your practice ?
the results are shown in figure 3 , showing moderate levels of adoption but no use in about 50% of respondents .
( another bias to note for these questions is that several people from the same institution may have responded ) .
current use of digital pathology among survey respondents the same question was asked for the predicted situation at the end of 2016 . as the 2016 prediction was also asked in the ndp2014 survey ,
as in the previous year , a vast majority expects to soon do digital to some degree , but the difference in predicted adoption rate indicates that the plans for digitization are progressing slightly slower than anticipated .
this development pace moderation is in line with reports from the symposium attendees that both funding allotment and procurement processes are causing delays in their digitization efforts . predicted use of digital pathology for primary review at the end of 2016 .
right : prediction from nordic symposium on digital pathology 2015 survey validation of digital pathology means controlling potential risks of the digitization step , i.e. , scanning and reproduction on a computer screen . in the college of american pathologists ( cap ) guidelines ,
wsi validation is defined as  a process that aims to demonstrate that the new method performs as expected for its intended use and environment prior to its application for patient care .
 an important aspect is to decide on an acceptable level of risk . while it is attractive to adopt zero tolerance for errors due to digitization , this may lead to an unbalanced distribution of efforts .
if the risks in other parts of the diagnostic chain are much larger than the ones in the digitization step , the mitigation and control efforts in those areas should come first .
therefore , to understand the perceived relative risk of digitization , the survey asked :  compared with other parts of the sample preparation and diagnostic process , how big do you think the added safety risk of the digitization step is ?  the results , presented in figure 5 , show that health care ndp attendees clearly consider the added risk from digitization to be smaller than risks in the diagnostic review , staining , sectioning , and grossing steps .
perceived added safety risk from digitization ( scanning and image reproduction on screen ) relative to risks stemming from other parts of the diagnostic pipeline .
overall , the results point to lower perceived risk , i.e. , that digitization is perceived as less error - prone there is an ongoing debate in the community regarding what type or scale of validation that is needed before adoption of digital pathology in diagnosis . to elicit the overall opinion ,
the survey asked :  what 's your personal view on the need for validation efforts to increase the confidence for digital pathology in clinical practice ?  for this group having substantial experience of clinical use of wsi , the dominant view ( 68% ) is that current knowledge is sufficient for going ahead with digital pathology adoption and that further validation is characterized as a continuous improvement effort .
this may again reflect the high proportion of early adopters in the audience . as seen in figure 6 ,
the majority sees further validation as a part of continued progress , but not as prohibitive for adoption in general validation can be performed , documented , and disseminated in many ways and by several types of stakeholders . as the decision to adopt digital pathology often boils down to the conviction of individuals
, it is interesting to know which sources of safety assurance that have the highest credibility .
the survey asked :  assurance that digital pathology is safe for clinical use can come from many sources . for your own decision ,
if digital pathology is safe , how much confidence would you get from the following sources ?  the results in figure 7 show that personal experience along with high - quality scientific trials is associated with the highest confidence , whereas ce marking and food and drug administration approval of systems are less assuring , relatively .
personal experience and high - quality trials are considered the most trustworthy sources after the survey results were presented , a guided discussion among all participants took place .
overall , the points of view shared demonstrated the many facets of validation to consider .
a fundamental prerequisite is that digital pathology does introduce new process steps that need to be scrutinized : the image digitization and the visualization ( display and interaction ) in a digital workstation .
there are now many concordance studies showing reassuring overall results . at the same time , potential concerns are that there are few well - designed large studies to date and that despite high overall concordance with light microscopy , this may conceal the possibility that for some case types , digitization might introduce problems not existing in microscope glass slide review . in line with the first statement of the cap guidelines , ndp attendees expressed the need for validation activities at each individual laboratory implementing wsi . in this preliminary stage , no clear consensus on scope and depth of such activities emerged from the discussion , but ongoing initiatives in sweden and the united kingdom are directed toward developing concrete support for validation work .
another aspect voiced was that even if agreeing that digital pathology adds a slight risk , this should be compared to the risk of nonadoption .
for example , an increased risk may be acceptable if the benefits of increased reproducibility or easier consultations across the healthcare enterprise clearly outweigh any additional risk .
a positive effect of the validation effort of digital pathology can also be that components of current practice , actually having evolved with a low level of scrutiny , are revisited with a critical eye .
the conclusion from the discussion is that there is a broad consensus in this group that continued efforts to scrutinize digital pathology are needed , whereas the views differ as to what degree this affects the pace of adoption .
paul j. van diest , professor and head of pathology at the university medical center utrecht , the netherlands , presented their digital pathology program , including both past efforts and future plans .
the experience includes many years of scanning all slides , working integration with their report system , and validation efforts with positive results .
currently , utrecht is implementing new systems and workflows to take the step to digital primary review , and prof .
van diest emphasized the need for establishing a solid and continuous change management process in the department , in contrast to a one - off implementation activity .
nasir rajpoot , associate professor at qatar university , qatar , and university of warwick , uk , gave a comprehensive overview of opportunities and challenges in image analysis for pathology .
he presented a wide range of methods developed in his research groups constituting a toolbox for detection and classification on several levels : nucleus , cell , gland , and entire tissue .
rajpoot also stressed the benefits of an open exchange of methods and data for the scientific community to effectively make advances in the field .
petra lindstedt , former head of the diagnostic division at region gvleborg , sweden , spoke to the benefits that had been the main motivation for their decision to go fully digital , a process now underway with several pathologists doing their main primary review on digital slides .
a benefit particular to smaller , rural hospitals is that a digital environment opens new possibilities for specialist careers based on a consultation volume from other providers .
johnny eriksson , cto at telemedicine clinic , spain , and cto radiology it at the university hospital rebro county , sweden , described the opportunities stemming from enterprise - wide digital image management .
the experience from radiology , including services such as running off - hour diagnostic routine for european hospitals from australia , demonstrates the potential but also the need to assiduously address the technical challenges involved .
anna bodn , pathologist and digitization project manager at linkping university hospital , sweden , presented the experiences from implementing a second generation of large - scale digital pathology in their clinic .
issues given increased consideration this time around included achieving highly stable and fast viewing , running scanners from multiple vendors in parallel , careful selection of monitors , and support for large slides .
manuel salto - tellez , professor and molecular pathologist at queen 's university belfast , uk , provided a compelling vision of improved health care , thanks to advances within reach for joint efforts in pathology and genomics .
several examples of such efforts from his research group were presented , including testing for braf , kras , and egfr mutations in cancer .
salto - tellez strongly emphasized the need for effectively combining the two disciplines of molecular and digital pathology , since the genomic findings require a context of phenotype and morphometry .
andr homeyer , scientist at the fraunhofer mevis research institute in bremen , germany , presented their group 's software framework for image analysis in pathology .
key objectives are to exploit image features across several scales and to meet high interactivity requirements by carefully designed feature extraction in the preprocessing stage .
simon hger of sectra , linkping , sweden , talked about how to construct a business case for digital pathology .
yee - wah tsang from coventry university , uk , presented the large validation study recently performed in coventry .
visiopharm arranged a talk from henrik holten - rossing from rigshospitalet copenhagen , denmark , presenting studies and experiences of advanced quantitative image analysis .
finally , a special session on education and collegial exchange was held , led by dr .
mats wolving , head of quality development at the swedish society of pathology and pathologist at sahlgrenska university hospital , gothenburg , sweden , and martin svenson of sectra .
they presented ongoing innovation efforts to develop new tools and workflows in this domain , and the audience contributed in an enlightening discussion regarding possibilities and obstacles with regards to this area of clinical practice .
a key part of the ndp program was the workshop discussing validation of digital pathology .
the workshop was organized as an open floor discussion with broad participation from the attendees . as an introduction
, a systematic review of previous digital pathology validation research was presented by bethany williams , leeds university . moreover ,
a survey among the health care attendees themselves , distributed in advance of the symposium , served as fuel for debate .
it is important to acknowledge that the survey respondents represent a biased selection among the pathology community .
since only ndp participants were asked , this means that respondents are likely to be among the most positive to digital pathology and also among the most experienced .
there is also a strong geographical dominance from the nordics and , in particular , sweden .
it is likely that the pathologist dominance was even higher for some questions that require deep knowledge of clinical practice .
role distribution of survey respondents the survey first asked :  today , to what degree do you use digital images of histology slides in your practice ? ( in percentage of all histology cases ) . 
the results are shown in figure 3 , showing moderate levels of adoption but no use in about 50% of respondents .
( another bias to note for these questions is that several people from the same institution may have responded ) .
current use of digital pathology among survey respondents the same question was asked for the predicted situation at the end of 2016 . as the 2016 prediction was also asked in the ndp2014 survey ,
, a vast majority expects to soon do digital to some degree , but the difference in predicted adoption rate indicates that the plans for digitization are progressing slightly slower than anticipated .
this development pace moderation is in line with reports from the symposium attendees that both funding allotment and procurement processes are causing delays in their digitization efforts . predicted use of digital pathology for primary review at the end of 2016 .
right : prediction from nordic symposium on digital pathology 2015 survey validation of digital pathology means controlling potential risks of the digitization step , i.e. , scanning and reproduction on a computer screen . in the college of american pathologists ( cap ) guidelines ,
wsi validation is defined as  a process that aims to demonstrate that the new method performs as expected for its intended use and environment prior to its application for patient care .
while it is attractive to adopt zero tolerance for errors due to digitization , this may lead to an unbalanced distribution of efforts .
if the risks in other parts of the diagnostic chain are much larger than the ones in the digitization step , the mitigation and control efforts in those areas should come first .
therefore , to understand the perceived relative risk of digitization , the survey asked :  compared with other parts of the sample preparation and diagnostic process , how big do you think the added safety risk of the digitization step is ?  the results , presented in figure 5 , show that health care ndp attendees clearly consider the added risk from digitization to be smaller than risks in the diagnostic review , staining , sectioning , and grossing steps .
perceived added safety risk from digitization ( scanning and image reproduction on screen ) relative to risks stemming from other parts of the diagnostic pipeline .
overall , the results point to lower perceived risk , i.e. , that digitization is perceived as less error - prone there is an ongoing debate in the community regarding what type or scale of validation that is needed before adoption of digital pathology in diagnosis . to elicit the overall opinion ,
what 's your personal view on the need for validation efforts to increase the confidence for digital pathology in clinical practice ?  for this group having substantial experience of clinical use of wsi , the dominant view ( 68% ) is that current knowledge is sufficient for going ahead with digital pathology adoption and that further validation is characterized as a continuous improvement effort .
as seen in figure 6 , about 20% are more hesitant and require further validation as a condition for adoption .
the majority sees further validation as a part of continued progress , but not as prohibitive for adoption in general validation can be performed , documented , and disseminated in many ways and by several types of stakeholders . as the decision to adopt digital pathology often boils down to the conviction of individuals
, it is interesting to know which sources of safety assurance that have the highest credibility .
the survey asked :  assurance that digital pathology is safe for clinical use can come from many sources . for your own decision ,
if digital pathology is safe , how much confidence would you get from the following sources ? 
the results in figure 7 show that personal experience along with high - quality scientific trials is associated with the highest confidence , whereas ce marking and food and drug administration approval of systems are less assuring , relatively .
personal experience and high - quality trials are considered the most trustworthy sources after the survey results were presented , a guided discussion among all participants took place .
overall , the points of view shared demonstrated the many facets of validation to consider .
a fundamental prerequisite is that digital pathology does introduce new process steps that need to be scrutinized : the image digitization and the visualization ( display and interaction ) in a digital workstation .
there are now many concordance studies showing reassuring overall results . at the same time , potential concerns are that there are few well - designed large studies to date and that despite high overall concordance with light microscopy , this may conceal the possibility that for some case types , digitization might introduce problems not existing in microscope glass slide review . in line with the first statement of the cap guidelines , ndp attendees expressed the need for validation activities at each individual laboratory implementing wsi . in this preliminary stage
, no clear consensus on scope and depth of such activities emerged from the discussion , but ongoing initiatives in sweden and the united kingdom are directed toward developing concrete support for validation work .
another aspect voiced was that even if agreeing that digital pathology adds a slight risk , this should be compared to the risk of nonadoption .
for example , an increased risk may be acceptable if the benefits of increased reproducibility or easier consultations across the healthcare enterprise clearly outweigh any additional risk .
a positive effect of the validation effort of digital pathology can also be that components of current practice , actually having evolved with a low level of scrutiny , are revisited with a critical eye .
the conclusion from the discussion is that there is a broad consensus in this group that continued efforts to scrutinize digital pathology are needed , whereas the views differ as to what degree this affects the pace of adoption .
paul j. van diest , professor and head of pathology at the university medical center utrecht , the netherlands , presented their digital pathology program , including both past efforts and future plans .
the experience includes many years of scanning all slides , working integration with their report system , and validation efforts with positive results .
currently , utrecht is implementing new systems and workflows to take the step to digital primary review , and prof .
van diest emphasized the need for establishing a solid and continuous change management process in the department , in contrast to a one - off implementation activity .
nasir rajpoot , associate professor at qatar university , qatar , and university of warwick , uk , gave a comprehensive overview of opportunities and challenges in image analysis for pathology .
he presented a wide range of methods developed in his research groups constituting a toolbox for detection and classification on several levels : nucleus , cell , gland , and entire tissue .
dr . rajpoot also stressed the benefits of an open exchange of methods and data for the scientific community to effectively make advances in the field .
petra lindstedt , former head of the diagnostic division at region gvleborg , sweden , spoke to the benefits that had been the main motivation for their decision to go fully digital , a process now underway with several pathologists doing their main primary review on digital slides .
a benefit particular to smaller , rural hospitals is that a digital environment opens new possibilities for specialist careers based on a consultation volume from other providers .
johnny eriksson , cto at telemedicine clinic , spain , and cto radiology it at the university hospital rebro county , sweden , described the opportunities stemming from enterprise - wide digital image management .
the experience from radiology , including services such as running off - hour diagnostic routine for european hospitals from australia , demonstrates the potential but also the need to assiduously address the technical challenges involved .
anna bodn , pathologist and digitization project manager at linkping university hospital , sweden , presented the experiences from implementing a second generation of large - scale digital pathology in their clinic .
issues given increased consideration this time around included achieving highly stable and fast viewing , running scanners from multiple vendors in parallel , careful selection of monitors , and support for large slides .
manuel salto - tellez , professor and molecular pathologist at queen 's university belfast , uk , provided a compelling vision of improved health care , thanks to advances within reach for joint efforts in pathology and genomics .
several examples of such efforts from his research group were presented , including testing for braf , kras , and egfr mutations in cancer .
salto - tellez strongly emphasized the need for effectively combining the two disciplines of molecular and digital pathology , since the genomic findings require a context of phenotype and morphometry .
andr homeyer , scientist at the fraunhofer mevis research institute in bremen , germany , presented their group 's software framework for image analysis in pathology .
key objectives are to exploit image features across several scales and to meet high interactivity requirements by carefully designed feature extraction in the preprocessing stage .
simon hger of sectra , linkping , sweden , talked about how to construct a business case for digital pathology .
yee - wah tsang from coventry university , uk , presented the large validation study recently performed in coventry .
visiopharm arranged a talk from henrik holten - rossing from rigshospitalet copenhagen , denmark , presenting studies and experiences of advanced quantitative image analysis .
finally , a special session on education and collegial exchange was held , led by dr .
mats wolving , head of quality development at the swedish society of pathology and pathologist at sahlgrenska university hospital , gothenburg , sweden , and martin svenson of sectra .
they presented ongoing innovation efforts to develop new tools and workflows in this domain , and the audience contributed in an enlightening discussion regarding possibilities and obstacles with regards to this area of clinical practice .
the need for , and interest in , knowledge exchange with regards to the clinical routine use of wsi and related it tools continues to be strong , as demonstrated by the increasing attendance at this third installment of the ndp . as digital pathology evolves and initial hurdles are managed ,
the symposium touched on many topics of digital pathology , some of which are growing in importance with increased digital maturity .
the feedback from the attendees is that this type of experience sharing across organizations , disciplines , and sectors is important for the progress in the field . as organizers , we are happy to conclude that ndp 2015 has made a substantial contribution to this end . finally , we gladly note the increasing ratio of non - nordic attendees and encourage colleagues from all over the world to come and benefit from future ndp symposia .
darren treanor is a member of the aperio / leica advisory board and sectra advisory board .
darren treanor is a member of the aperio / leica advisory board and sectra advisory board .
 cross - disciplinary and cross - sectorial collaboration is a key success factor for turning the promise of digital pathology into actual clinical benefits . 
 the nordic symposium on digital pathology ( ndp ) was created to promote knowledge exchange in this area , among stakeholders in health care , industry , and academia . 
 this article is a summary of the third ndp symposium in linkping , sweden . 
 the nordic experiences , including several hospitals using whole - slide imaging for substantial parts of their primary reviews , formed a fertile base for discussions among the 190 ndp attendees originating from 15 different countries . 
 this summary also contains results from a survey on adoption and validation aspects of clinical digital pathology use . 
INTRODUCTION
MEETING OVERVIEW
Workshop on Validation of Digital Pathology
Speaker Contributions
CONCLUSIONS
Financial Support and Sponsorship
Conflicts of Interest