Profile – Perk Lab

Natasja Janssen

Postdoctoral Researcher

School of Computing

Queen's University

Natasja Janssen received her BSc and Msc in Technical Medicine from the University of Twente in Enschede, the Netherlands. She graduated in 2013 and started to work in the Netherlands Cancer Institute as a PhD student at both the departments of radiation and surgical oncology. Her PhD research was focused on improving surgical outcome for patients with non-palpable breast cancer in which she worked closely together with a variety of clinicians such as radiation oncologists, radiologists, surgical oncologists and pathologists but also physicists and computer engineers. In September 2018 she defended her PhD thesis 'Navigating towards the unseen margins of non-palpable breast cancer' at the University of Amsterdam. She is now working as a post-doctoral researcher in the Perk Lab. Her research interests remain image-guided medical interventions and surgical navigation, aiming to improve patient outcome.

Natasja is a Perk Lab alumna, returned to academia in The Netherlands.

Janssen, Natasja; Kaufmann, Martin; Santilli, Alice; Jamzad, Amoon; Kaitlin, Vanderbeck; Ren, Kevin; Ungi, Tamas; Mousavi, Parvin; Rudan, John; McKay, Doug; Wang, Amy; Fichtinger, Gabor

Navigated tissue characterization during skin cancer surgery Journal Article

In: Int J Comput Assist Radiol Surg, 2020.

Abstract | Links | BibTeX

@article{Janssen2020a,

title = {Navigated tissue characterization during skin cancer surgery},

author = {Natasja Janssen and Martin Kaufmann and Alice Santilli and Amoon Jamzad and Vanderbeck Kaitlin and Kevin Ren and Tamas Ungi and Parvin Mousavi and John Rudan and Doug McKay and Amy Wang and Gabor Fichtinger},

url = {https://doi.org/10.1007/s11548-020-02200-4},

doi = {10.1007/s11548-020-02200-4},

year  = {2020},

date = {2020-01-01},

journal = {Int J Comput Assist Radiol Surg},

abstract = {<p><strong>Purpose: </strong>Basal cell carcinoma (BCC) is the most commonly diagnosed skin cancer and is treated by surgical resection. Incomplete tumor removal requires surgical revision, leading to significant healthcare costs and impaired cosmesis. We investigated the clinical feasibility of a surgical navigation system for BCC surgery, based on molecular tissue characterization using rapid evaporative ionization mass spectrometry (REIMS).</p> 

<p><strong>Methods: </strong>REIMS enables direct tissue characterization by analysis of cell-specific molecules present within surgical smoke, produced during electrocautery tissue resection. A tissue characterization model was built by acquiring REIMS spectra of BCC, healthy skin and fat from ex vivo skin cancer specimens. This model was used for tissue characterization during navigated skin cancer surgery. Navigation was enabled by optical tracking and real-time visualization of the cautery relative to a contoured resection volume. The surgical smoke was aspirated into a mass spectrometer and directly analyzed with REIMS. Classified BCC was annotated at the real-time position of the cautery. Feasibility of the navigation system, and tissue classification accuracy for ex vivo and intraoperative surgery were evaluated.</p> 

<p><strong>Results: </strong>Fifty-four fresh excision specimens were used to build the ex vivo model of BCC, normal skin and fat, with 92% accuracy. While 3 surgeries were successfully navigated without breach of sterility, the intraoperative performance of the ex vivo model was low (< 50%). Hypotheses are: (1) the model was trained on heterogeneous mass spectra that did not originate from a single tissue type, (2) during surgery mixed tissue types were resected and thus presented to the model, and (3) the mass spectra were not validated by pathology.</p> 

<p><strong>Conclusion: </strong>REIMS-navigated skin cancer surgery has the potential to detect and localize remaining tumor intraoperatively. Future work will be focused on improving our model by using a precise pencil cautery tip for burning localized tissue types, and having pathology-validated mass spectra.</p>},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

Purpose: Basal cell carcinoma (BCC) is the most commonly diagnosed skin cancer and is treated by surgical resection. Incomplete tumor removal requires surgical revision, leading to significant healthcare costs and impaired cosmesis. We investigated the clinical feasibility of a surgical navigation system for BCC surgery, based on molecular tissue characterization using rapid evaporative ionization mass spectrometry (REIMS).
Methods: REIMS enables direct tissue characterization by analysis of cell-specific molecules present within surgical smoke, produced during electrocautery tissue resection. A tissue characterization model was built by acquiring REIMS spectra of BCC, healthy skin and fat from ex vivo skin cancer specimens. This model was used for tissue characterization during navigated skin cancer surgery. Navigation was enabled by optical tracking and real-time visualization of the cautery relative to a contoured resection volume. The surgical smoke was aspirated into a mass spectrometer and directly analyzed with REIMS. Classified BCC was annotated at the real-time position of the cautery. Feasibility of the navigation system, and tissue classification accuracy for ex vivo and intraoperative surgery were evaluated.
Results: Fifty-four fresh excision specimens were used to build the ex vivo model of BCC, normal skin and fat, with 92% accuracy. While 3 surgeries were successfully navigated without breach of sterility, the intraoperative performance of the ex vivo model was low (< 50%). Hypotheses are: (1) the model was trained on heterogeneous mass spectra that did not originate from a single tissue type, (2) during surgery mixed tissue types were resected and thus presented to the model, and (3) the mass spectra were not validated by pathology.
Conclusion: REIMS-navigated skin cancer surgery has the potential to detect and localize remaining tumor intraoperatively. Future work will be focused on improving our model by using a precise pencil cautery tip for burning localized tissue types, and having pathology-validated mass spectra.