title: Optical coherence tomography spectral analysis for detecting apoptosis in vitro and in vivo.
abstract: Apoptosis is a form of programmed cell death characterized by a series of predictable morphological changes at the subcellular level, which modify the light-scattering properties of cells. We present a spectroscopic optical coherence tomography (OCT) technique to detect changes in subcellular morphology related to apoptosis in vitro and in vivo. OCT data were acquired from acute myeloid leukemia (AML) cells treated with cisplatin over a 48-h period. The backscatter spectrum of the OCT signal acquired from the cell samples was characterized by calculating its in vitro integrated backscatter (IB) and spectral slope (SS). The IB increased with treatment duration, while the SS decreased, with the most significant changes occurring after 24 to 48 h of treatment. These changes coincided with striking morphological transformations in the cells and their nuclei. Similar trends in the spectral parameter values were observed in vivo in solid tumors grown from AML cells in mice, which were treated with chemotherapy and radiation. Our results provide a strong foundation from which future experiments may be designed to further understand the effect of cellular morphology and kinetics of apoptosis on the OCT signal and demonstrate the feasibility of using this technique in vivo.
authors.affiliation: University of Toronto, Department of Medical Biophysics, Faculty of Medicine, 2075 Bayview Avenue, Toronto M4N 3M5, CanadabSunnybrook Health Sciences Centre, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto M4N 3M5, CanadacSunnybrook Health Sci.
authors.forename: Golnaz
authors.initials: G
authors.lastname: Farhat
authors.affiliation: Sunnybrook Health Sciences Centre, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto M4N 3M5, CanadacSunnybrook Health Sciences Centre, Radiation Oncology, 2075 Bayview Avenue, Toronto M4N 3M5, Canada.
authors.forename: Anoja
authors.initials: A
authors.lastname: Giles
authors.affiliation: Ryerson University, Department of Physics, 350 Victoria Street, Toronto M5B 2K3, Canada.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Kolios
authors.affiliation: University of Toronto, Department of Medical Biophysics, Faculty of Medicine, 2075 Bayview Avenue, Toronto M4N 3M5, CanadabSunnybrook Health Sciences Centre, Sunnybrook Research Institute, 2075 Bayview Avenue, Toronto M4N 3M5, CanadacSunnybrook Health Sci.
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Czarnota
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000627:therapeutic use; D017209:Apoptosis; D002138:Calibration; D002945:Cisplatin / Q000627:therapeutic use; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000188:drug therapy / Q000473:pathology* / Q000532:radiotherapy; D051379:Mice; D016513:Mice, SCID; D009368:Neoplasm Transplantation; D012542:Scattering, Radiation; D013053:Spectrophotometry / Q000379:methods*; D041623:Tomography, Optical Coherence / Q000379:methods*
chemical_list: D000970:Antineoplastic Agents; D002945:Cisplatin