Advanced Image-Guidance and Fluorescence-Guidance Products for Brain Tumor Resection

Insight Surgical is developing technologies to enable updating of image guidance throughout the surgical procedure to increase navigation accuracy and to enhance fluorescence sensitivity for improved  tumor detection.

Image-Guided Neurosurgery

Over the past four decades surgical navigation systems based upon co-registration of pre-operative imaging with the surgical field have been developed and widely-adopted. During an operation, a surgeon is able to see the location of a surgical instrument displayed on preoperative MRI or CT images (much like a GPS system) and imaging information (such as a tumor contour) is superposed on the surgical field on a heads-up display, headset or other augmented reality device.

  • Pre-surgical plans for tumor resection or other pathology can be executed in the operating room with accuracy and precision far exceeding that of unaided intervention.
  • In robotic surgery, a surgical instrument can be placed at the desired location and orientation.
  • Use of image-guidance is near-universal today for neurosurgical procedures and the technology has spread to other surgical specialties.

Brain Shifts During Tumor Resection

While commercial image guidance systems have been refined and enhanced, the fundamental and critical limitation of the technology — its inability to account for movement and deformation of tissue during surgery (“brain shift”) — remains unsolved.

Since image guidance depends upon accurate co-registration of imaging and the evolving surgical field, conventional systems that achieve initial accuracies of 2mm or better deteriorate in accuracy soon after surgery begins. This error has been characterized by multiple groups and averages between 6 and 10 mm (a very undesirable degree of inaccuracy), with maximum error as great as 2.5 centimeters.1,2,3,4,5

The video above shows how the brain shifts during surgery.

While commercial image guidance systems have been refined and enhanced, the fundamental and critical limitation of the technology — its inability to account for movement and deformation of tissue during surgery (“brain shift”) — remains unsolved.

Since image guidance depends upon accurate co-registration of imaging and the evolving surgical field, conventional systems that achieve initial accuracies of 2mm or better deteriorate in accuracy soon after surgery begins. This error has been characterized by multiple groups and averages between 6 and 10 mm (a very undesirable degree of inaccuracy), with maximum error as great as 2.5 centimeters. 1,2,3,4,5

The video above shows how the brain shifts during surgery.

Insight Surgical is developing I2 UPDATE™

I2 UPDATE is an innovative technology designed to maintain image-guidance accuracy to better than 2mm throughout the surgical procedure. Updating is AUTOMATIC, and DOES NOT INTERRUPT the surgical work-flow. I2 UPDATE can be integrated into any image-guidance system and does not require intraoperative iand does not require intraoperative ultrasound, MR or CT imaging.
  • Unique solution for brain shift.
  • Seamless, non-intrusive, accurate MR updates of the evolving neurosurgical field.

Fluorescence-Guided Neurosurgery

Fluorescence guidance is a neurosurgical imaging technique that uses administered or endogenous fluorescent dyes or contrast agents to enhance visualization of tumor or other specific tissue structures within the brain during surgery. The technique is particularly valuable for neurosurgeons because it helps them identify and differentiate tumor from critical normal tissue, improving the precision and completeness of tumor resection.6

Fluorescence guidance includes the use of:

Fluorescence guidance is a neurosurgical imaging technique that uses administered or endogenous fluorescent dyes or contrast agents to enhance visualization of tumor or other specific tissue structures within the brain during surgery. The technique is particularly valuable for neurosurgeons because it helps them identify and differentiate tumor from critical normal tissue, improving the precision and completeness of tumor resection.6

Fluorescence guidance includes the use of:

  • Fluorophores or their fluorophore pro-drugs: These agents may distribute with vascular permeability, may preferentionally accumulate in tumor, or selectively bind to specific targets associated with tumor.
  • Illumination: Once the agent has been administered and has accumulated in the target tissue, the surgical field is illuminated with a specific wavelength of excitation light. These molecules then emit fluorescent light that is visible to the eye or special imaging equipment.
  • Imaging Equipment: Specialized imaging equipment, such as fluorescence microscopes or cameras fitted with suitable filters, are used to capture the emitted fluorescent light.
  • Real-Time Visualization: The captured fluorescent images are displayed in real-time on a monitor or heads-up display, enabling the surgeon to see the enhanced contrast between the target tissue and the surrounding healthy tissue. This improved visualization can help the surgeon make more accurate decisions during the procedure.

Insight Surgical is Developing

Quantitative Fluorescence Technology

qF-IMAGE™

A system for wide-field detection of non-visible fluorescence

qF-IMAGE™ is designed to provide neurosurgeons with highly sensitive, objective, in vivo fluorescence detection and quantitative determination of fluorophore concentration, based on proprietary algorithms for real-time spectroscopic analysis and correction for the effects of light attenuation by the tissue. Our technology is designed to address existing limitations associated with current fluorescence detection technologies that rely on subjective visual assessment by the neurosurgeon.

 

qF-PROBE™

Point spectroscopy detection system for tissue characterization

qF-PROBE™ is an intraoperative probe that, when touched to the tissue, is designed to rapidly identify the spectral signature of the fluorophore. In institutional IRB-approved clinical studies using a non-FDA-approved prototype device, such technology was shown to be up to 100 times more sensitive than conventional visual perception of fluorescence.7

 

qF-PROBE™ is an intraoperative probe that, when touched to the tissue, is designed to rapidly identify the spectral signature of the fluorophore. In institutional IRB-approved clinical studies using a non-FDA-approved prototype device, such technology was shown to be up to 100 times more sensitive than conventional visual perception of fluorescence.7

 

References

  1. Roberts DW, Hartov A, Kennedy FE, Miga MI, Paulsen KD:  Intraoperative brain shift and deformation: a quantitative analysis of cortical displacement in 28 cases.  Neurosurgery  43:749-760, 1998.
  2. Fan X, Roberts DW, Schaewe TJ, Ji S, Holton LH, Simon DA, Paulsen KD. Intraoperative image updating for brain shift following dural opening. J Neurosurg 126:1924-1933, 2017. PubMed PMID: 27611206. PMCID: PMC5549265.
  3. Fan X, Roberts DW, Olson JD, Ji S, Schwaewe, Simon DA, Paulsen KD. Image updating for brain shift compensation during resection. Operative Neurosurgery 14:402-411, 2018. DOI: 10.1093/ons/opx123.
  4. Dorward NL, Alberti O, Velani B et al, Postimaging brain distortion: magnitude, correlates, and impact on neuronavigation. J Neurosurg 88:656-662, 1998.
  5. Nimsky C, Ganslandt O, Hastreiter P, Fahlbusch R. Intraoperative compensation for brain shift. Surg Neurol 56:357-365, 2001.
  6. Stummer W, Pichlmeier U, Meinel T, Wiestler OD, Zanella F, Reulen HJ: Fluorescence-guided surgery with 5-aminolevulinic acid for resection of malignant glioma: a randomized controlled multicentre phase III trial. Lancet Oncol 7:392–401, 2006.
  7. Valdes PA, Leblond F, Kim A, Harris BT, Wilson BC, Fan X, Tosteson TD, Hartov A, Ji S, Erkmen K, Simmons NE, Paulsen KD, Roberts DW: Quantitative fluorescence in intracranial tumor: implications for ALA-induced PpIX as an intraoperative biomarker.  J Neurosurg 115(1):11-17, Jul 2011 [epub 2011 Mar 25]. PMID: 21529179]