Imaging as real time assistant during surgery in new perspective

Removing all cancer tissue is one of the most important outcome parameters in oncologic surgery. However, no clinical tools are available during surgery that can assist the surgeon in real-time. To date, the surgeon receives the pathology result from the pathologist a few days after the surgery has been completed, thereby missing the opportunity to directly act on the obtained surgical excision results.

The pathological assessment of surgical specimens during surgery can reduce the incidence of positive resection margins, which otherwise can result in additional surgeries or aggressive postoperative therapeutic regimens. To improve patient outcomes, intraoperative spectroscopic, fluorescence-based, structural, optoacoustic and radiological imaging techniques are being tested on freshly excised tissue.

Outlook on intraoperative pathology-assisted surgery

Tumour-positive margins are an unwanted postoperative outcome, unfortunately occurring in too many cases. Imaging techniques that can selectively and accurately detect cancers intraoperatively will improve surgery outcomes and ultimately survival rates. Several imaging techniques could in principle enhance the detection of a broad range of tumour types before and during surgery. 

However, most clinical studies and improvements have focused mainly on in vivo tumour detection, and relatively few studies have been carried out on imaging-assisted assessments of the specimen immediately after excision. Incorporating intraoperative pathology-assisted surgery (IPAS) in clinical workflows for the assessment of surgical specimens would open up new possibilities in the  pathological assessment of excised tissue. Further research in imaging techniques for enhanced tumour detection during surgery are therefore highly needed. 

Implementing IPAS

Adequate clinical implementation of IPAS techniques would require consideration of several technical and clinical factors. 

The following key technical requirements would need improving:

  • Image resolution 
  • Penetration depth 
  • Field of view and acquisition time

These factors can be differently prioritized depending on the specific clinical indication. The clinical implementation of IPAS will require rigorous and standardized pre-operative planning. A first step would be to determine whether endogenous contrast is sufficient or whether exogenous (targeted) contrast agents are required.

User-friendly and fast implementation is crucial

Regardless, and most importantly for clinicians, the imaging technique should be user-friendly and easy and fast to implement. Clinical trials assessing IPAS should be designed to provide clinical evidence of whether there is added value for clinicians, such as tumour-negative surgical margins and enhanced tumour detection that assist clinical decision-making. Lessons could be learned from the in vivo image-guided surgery techniques that were at the same point of development about a decade ago and that are currently being assessed in phase II and phase III clinical studies. Most importantly, the gaps between technical challenges and clinical needs need to be bridged.

In the recent publication in Nature Biomedical Engineering Voskuil, Vonk and colleagues tell you all about their perspective on intraoperative pathology-assisted surgery.
Read the publication: Intraoperative imaging in pathology-assisted surgery

Next steps

As a next step, in a collaboration between the department of Molecular Biophysics at the Zernike Institute of the Faculty of Science and Engineering and the University Medical Center Groningen, the research group hopes to further explore intraoperative pathology-assisted surgery in the clinical setting for the benefit of cancer patients, whereas TRACER BV assists in valorization for potential commercial development of future devices.
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