Intraoperative confocal laser endomicroscopy: prospective in vivo feasibility study of a clinical-grade system for brain tumors

Irakliy Abramov, The Loyal and Edith Davis Neurosurgical Research Laboratory, Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix.Follow
Marian T. Park, The Loyal and Edith Davis Neurosurgical Research Laboratory, Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix.
Evgenii Belykh, Department of Neurosurgery, Rutgers New Jersey Medical School, Newark, New Jersey.Follow
Alexander B. Dru, The Loyal and Edith Davis Neurosurgical Research Laboratory, Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix.
Yuan Xu, The Loyal and Edith Davis Neurosurgical Research Laboratory, Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix.
Timothy C. Gooldy, Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix.
Lea Scherschinski, Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix.
S Harrison Farber, Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix.
Andrew S. Little, Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix.Follow
Randall W. Porter, Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix.
Kris A. Smith, Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix.
Michael T. Lawton, Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix.Follow
Jennifer M. Eschbacher, Department of Neuropathology, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona; and.Follow
Mark C. Preul, The Loyal and Edith Davis Neurosurgical Research Laboratory, Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix.

Document Type

Article

Abstract

OBJECTIVE: The authors evaluated the feasibility of using the first clinical-grade confocal laser endomicroscopy (CLE) system using fluorescein sodium for intraoperative in vivo imaging of brain tumors. METHODS: A CLE system cleared by the FDA was used in 30 prospectively enrolled patients with 31 brain tumors (13 gliomas, 5 meningiomas, 6 other primary tumors, 3 metastases, and 4 reactive brain tissue). A neuropathologist classified CLE images as interpretable or noninterpretable. Images were compared with corresponding frozen and permanent histology sections, with image correlation to biopsy location using neuronavigation. The specificities and sensitivities of CLE images and frozen sections were calculated using permanent histological sections as the standard for comparison. A recently developed surgical telepathology software platform was used in 11 cases to provide real-time intraoperative consultation with a neuropathologist. RESULTS: Overall, 10,713 CLE images from 335 regions of interest were acquired. The mean duration of the use of the CLE system was 7 minutes (range 3-18 minutes). Interpretable CLE images were obtained in all cases. The first interpretable image was acquired within a mean of 6 (SD 10) images and within the first 5 (SD 13) seconds of imaging; 4896 images (46%) were interpretable. Interpretable image acquisition was positively correlated with study progression, number of cases per surgeon, cumulative length of CLE time, and CLE time per case (p ≤ 0.01). The diagnostic accuracy, sensitivity, and specificity of CLE compared with frozen sections were 94%, 94%, and 100%, respectively, and the diagnostic accuracy, sensitivity, and specificity of CLE compared with permanent histological sections were 92%, 90%, and 94%, respectively. No difference was observed between lesion types for the time to first interpretable image (p = 0.35). Deeply located lesions were associated with a higher percentage of interpretable images than superficial lesions (p = 0.02). The study met the primary end points, confirming the safety and feasibility and acquisition of noninvasive digital biopsies in all cases. The study met the secondary end points for the duration of CLE use necessary to obtain interpretable images. A neuropathologist could interpret the CLE images in 29 (97%) of 30 cases. CONCLUSIONS: The clinical-grade CLE system allows in vivo, intraoperative, high-resolution cellular visualization of tissue microstructure and identification of lesional tissue patterns in real time, without the need for tissue preparation.

Medical Subject Headings

Humans; Feasibility Studies; Prospective Studies; Microscopy, Confocal (methods); Brain Neoplasms (surgery); Lasers

Publication Date

3-1-2023

Publication Title

Journal of neurosurgery

E-ISSN

1933-0693

Volume

138

Issue

3

First Page

587

Last Page

597

PubMed ID

35901698

Digital Object Identifier (DOI)

10.3171/2022.5.JNS2282

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