Remission spectrometry for blood vessel detection during stereotactic biopsy of brain tumors

• Published in: Journal of biophotonics 2017-08, Vol.10 (8), p.1080-1094
• Main Authors: Markwardt, Niklas A., Stepp, Herbert, Franz, Gerhard, Sroka, Ronald, Goetz, Marcus, Zelenkov, Petr, Rühm, Adrian
• Format: Article
• Language: English
• Subjects: Animals; Biopsy; Biopsy - methods; blood vessel detection; Blood vessels; Brain; Brain - blood supply; Brain - diagnostic imaging; Brain cancer; Brain Neoplasms - blood supply; Brain Neoplasms - diagnostic imaging; Brain tumors; Cutting parameters; Diagnostic systems; glioblastoma multiforme; Hemoglobin; Hemorrhage; Light; Luminous intensity; Morbidity; optical phantoms; Oxygenation; Ray tracing; ray tracing simulations; Remission; Spectrometry; Spectrum Analysis; stereotactic biopsy; Stereotaxic Techniques; Swine; Tumors
• ISSN: 1864-063X; 1864-0648
• DOI: 10.1002/jbio.201600193

Stereotactic biopsy is used to enable diagnostic confirmation of brain tumors and treatment planning. Despite being a well‐established technique, it is related to significant morbidity and mortality rates mostly caused by hemorrhages due to blood vessel ruptures. This paper presents a method of vessel detection during stereotactic biopsy that can be easily implemented by integrating two side‐view fibers into a conventional side‐cutting biopsy needle. Tissue within the needle window is illuminated through the first fiber; the second fiber detects the remitted light. By taking the ratio of the intensities at two wavelengths with strongly differing hemoglobin absorption, blood vessels can be recognized immediately before biopsy sampling. Via ray tracing simulations and phantom experiments, the dependency of the remission ratio R = I578/I650 on various parameters (blood oxygenation, fiber‐to‐vessel and inter‐fiber distance, vessel diameter and orientation) was investigated for a bare‐fiber probe. Up to 800–1200 µm away from the probe, a vessel can be recognized by a considerable reduction of the remission ratio from the background level. The technique was also successfully tested with a real biopsy needle probe on both optical phantoms and ex‐vivo porcine brain tissue, thus showing potential to improve the safety of stereotactic biopsy. Dual‐wavelength remission measurement for the detection of blood vessels during stereotactic biopsy. To increase the safety of stereotactic brain biopsies, it is crucial to avoid hemorrhages due to blood vessel rupture. By illuminating the tissue that is to be sampled and comparing the remitted intensities at two wavelengths with strongly differing hemoglobin absorption, blood vessels can be recognized before biopsy sampling. The method is easily implementable into a conventional biopsy needle and clearly discriminates between vessels within and outside the needle's coverage.