In vivo multiphoton tomography and fluorescence lifetime imaging of human brain tumor tissue

Abstract

High resolution multiphoton tomography and fluorescence lifetime imaging differentiates glioma from adjacent brain in native tissue samples ex vivo. Presently, multiphoton tomography is applied in clinical dermatology and experimentally. We here present the first application of multiphoton and fluorescence lifetime imaging for in vivo imaging on humans during a neurosurgical procedure. We used a MPTflex™ Multiphoton Laser Tomograph (JenLab, Germany). We examined cultured glioma cells in an orthotopic mouse tumor model and native human tissue samples. Finally the multiphoton tomograph was applied to provide optical biopsies during resection of a clinical case of glioblastoma. All tissues imaged by multiphoton tomography were sampled and processed for conventional histopathology. The multiphoton tomograph allowed fluorescence intensity- and fluorescence lifetime imaging with submicron spatial resolution and 200 picosecond temporal resolution. Morphological fluorescence intensity imaging and fluorescence lifetime imaging of tumor-bearing mouse brains and native human tissue samples clearly differentiated tumor and adjacent brain tissue. Intraoperative imaging was found to be technically feasible. Intraoperative image quality was comparable to ex vivo examinations. To our knowledge we here present the first intraoperative application of high resolution multiphoton tomography and fluorescence lifetime imaging of human brain tumors in situ. It allowed in vivo identification and determination of cell density of tumor tissue on a cellular and subcellular level within seconds. The technology shows the potential of rapid intraoperative identification of native glioma tissue without need for tissue processing or staining.

Applications of fluorescence lifetime imaging in clinical medicine

“…at the cellular and subcellular levels without tissue treatment or staining to identify glioma tissue, 33,34 as shown in Fig. 6.…”

Cross-Polarization Optical Coherence Tomography in Comparative in vivo and ex vivo Studies of the Optical Properties of Normal and Tumorous Brain Tissues

“…Optical bioimaging techniques are most promising in this regard [9], where optical coherence tomography (OCT) [10] and multiphoton microscopy/tomography [11] are capable of visualizing cyto-and myelo-architectonics of the brain.…”

Metabolic Imaging in the Study of Oncological Processes (Review)

“…There is equipment for two-photon microscopy and FlIM, approved for application in clinic, such as MPTflex and DermaInspect systems produced by Jenlab (Germany) [3,96,97].…”

“…Thus, NADH lifetime has proved to be considerably shorter in melanoma cells than in those of basalioma and this can serve as a criterion for differential diagnosis [97]. The first study has shown FLIM applicability for evaluating resection borders during neurosurgical intervention on brain tumor in vivo [96]. FlIM spectroscopy has been used in patients with head and neck tumors to reveal that tumor tissue cells have shorter NADH fluorescence lifetime as compared to the surrounding healthy tissue [108][109][110], which suggests their glycolytic status.…”