1. 1-15 of 15
    1. Optical coherence tomography detects necrotic regions and volumetrically quantifies multicellular tumor spheroids

      Optical coherence tomography detects necrotic regions and volumetrically quantifies multicellular tumor spheroids

      hree-dimensional (3D) tumor spheroid models have gained increased recognition as important tools in cancer research and anti-cancer drug development. However, currently available imaging approaches employed in high-throughput screening drug discovery platforms e.g. bright field, phase contrast, and fluorescence microscopies, are unable to resolve 3D structures deep inside (>50 μm) tumor spheroids. In this study, we established a label-free, non-invasive optical coherence tomography (OCT) imaging platform to characterize 3D morphological and physiological information of multicellular tumor spheroids (MCTS) growing from ~250 μm up to ~600 μm in height over 21 days. In particular, tumor spheroids of two cell lines glioblastoma ...

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    2. Wide-field optical coherence tomography (WF-OCT) for near real-time, point-of-care assessment of margin status in breast-conserving surgery specimens: Results of a feasibility study at a high-volume single-centre

      Wide-field optical coherence tomography (WF-OCT) for near real-time, point-of-care assessment of margin status in breast-conserving surgery specimens: Results of a feasibility study at a high-volume single-centre

      Wide-Field Optical Coherence Tomography (WF-OCT) is a non-destructive, non-contact light imaging modality capable of label-free visualization of the internal microscopic architecture of breast tissue specimens. Its unique combination of high-resolution imaging in near real-time with tissue penetration depths approaching 2-mm makes it a promising imaging modality for obtaining detailed surgical margin status in breast-conserving surgery (BCS) specimens. A prototype WF-OCT imaging platform developed by Perimeter Medical Imaging, Inc. (Toronto, Canada) has permitted fully-automated, dynamically-focused visualization of margin widths around the intact surfaces of freshly excised BCS specimens. Herein are reported the results of a feasibility study at a high-volume single-centre ...

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    3. Real-time Imaging of the Resection Bed Using a Handheld Probe to Reduce Incidence of Microscopic Positive Margins in Cancer Surgery

      Real-time Imaging of the Resection Bed Using a Handheld Probe to Reduce Incidence of Microscopic Positive Margins in Cancer Surgery

      Wide local excision (WLE) is a common surgical intervention for solid tumors such as those in melanoma, breast, pancreatic, and gastrointestinal cancer. However, adequate margin assessment during WLE remains a significant challenge, resulting in surgical reinterventions to achieve adequate local control. Currently, no label-free imaging method is available for surgeons to examine the resection bed in vivo for microscopic residual cancer. Optical coherence tomography (OCT) enables real-time high-resolution imaging of tissue microstructure. Previous studies have demonstrated that OCT analysis of excised tissue specimens can distinguish between normal and cancerous tissues by identifying the heterogeneous and disorganized microscopic tissue structures indicative ...

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    4. Investigation of optical coherence micro-elastography as a method to visualize cancers in human breast tissue

      Investigation of optical coherence micro-elastography as a method to visualize cancers in human breast tissue

      Accurate intraoperative identification of malignant tissue is a challenge in the surgical management of breast cancer. Imaging techniques that help address this challenge could contribute to more complete and accurate tumor excision, and thereby help reduce the current high re-excision rates without resorting to the removal of excess healthy tissue. Optical coherence micro-elastography (OCME) is a three-dimensional, high-resolution imaging technique that is sensitive to micro-scale variations of the mechanical properties of tissue. As tumor modifies the mechanical properties of breast tissue, OCME has the potential to identify, on the micro-scale, involved regions of fresh, unstained tissue. OCME is based on ...

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    5. Polarization Sensitive Multimodal Imaging for Detecting Breast Cancer

      Polarization Sensitive Multimodal Imaging for Detecting Breast Cancer

      Intra-operative delineation of breast cancer is a significant problem in surgical oncology. A reliable method for demarcation of malignant breast tissue during surgery would reduce the re-excision rate due to positive margins. We present a novel method of identifying breast cancer margins using combined dye-enhanced wide-field fluorescence polarization (FP) imaging for en face cancer margins and polarization sensitive (PS) optical coherence tomography (OCT) for cross-sectional evaluation. Tumor specimens were collected following breast surgery, stained with methylene blue, and imaged. Wide-field FP images were excited at 640 nm and registered between 660 and 750 nm. Standard and PS OCT images were ...

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    6. Intraoperative assessment of tumor margins with a new optical imaging technology: A multi-center, randomized, blinded clinical trial

      Intraoperative assessment of tumor margins with a new optical imaging technology: A multi-center, randomized, blinded clinical trial

      Background: Partial mastectomy is the most commonly performed procedure for invasive breast cancer and is associated with a reexcision rate commonly ranging from 20% to 40% in the literature. This high rate of reexcision is associated with significant additional cost (estimated over $4,000 per reexcision) and lower quality outcomes. Optical coherence tomography (OCT) is a high-resolution imaging technology that images tissue structure with micron-scale resolution – on the same scale as histopathology. It is similar to ultrasound except it uses near infra-red light waves instead of sound waves to create detailed images several millimeters deep into tissue. Although widely used ...

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    7. The potential use of Optical Coherence Tomography for intraoperative breast tumour margin width estimation

      The potential use of Optical Coherence Tomography for intraoperative breast tumour margin width estimation

      Total mastectomy and lumpectomy with radiation have been shown to have equivalent patient outcomes, which has likely contributed to the more widespread adoption of breast conserving surgery (BCS) procedures. Assessment of breast lumpectomy margin widths in both an accurate and timely manner is essential to successful breast conservation procedures. Current BCS methodologies have been reported to result in reoperation rates of up to 20–60%, which represents a significant and unmet need for improved margin assessment. High reoperation rates present both increased treatment risk to patients and increased burden on healthcare systems. In the USA alone, over 150,000 lumpectomies ...

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    8. Molecular Histopathology by Spectrally Reconstructed Nonlinear Interferometric Vibrational Imaging

      Molecular Histopathology by Spectrally Reconstructed Nonlinear Interferometric Vibrational Imaging
      Sensitive assays for rapid quantitative analysis of histologic sections, resected tissue specimens, or in situ tissue are highly desired for early disease diagnosis. Stained histopathology is the gold standard but remains a subjective practice on processed tissue taking from hours to days. We describe a microscopy technique that obtains a sensitive and accurate color-coded image from intrinsic molecular markers. Spectrally reconstructed nonlinear interferometric vibrational imaging can differentiate cancer versus normal tissue sections with greater than 99% confidence interval in a preclinical rat breast cancer model and define cancer boundaries to ±100 μm with greater than 99% confidence interval, using fresh ...
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    9. Integrated Optical Coherence Tomography and Microscopy for Ex Vivo Multiscale Evaluation of Human Breast Tissues

      Integrated Optical Coherence Tomography and Microscopy for Ex Vivo Multiscale Evaluation of Human Breast Tissues

      3D tissue imaging methods are expected to improve surgical management of cancer. In this study, we examined the feasibility of two 3D imaging technologies, optical coherence tomography (OCT) and optical coherence microscopy (OCM), to view human breast specimens based on intrinsic optical contrast. Specifically, we imaged 44 ex vivo breast specimens including 34 benign and 10 malignant lesions with an integrated OCT and OCM system developed in our laboratory. The system enabled 4 um axial resolution (OCT and OCM) with 14 um (OCT) and 2 um (OCM) transverse resolution, respectively. OCT and OCM images were compared with corresponding histologic sections ...

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    10. Imaging of Human Lymph Nodes Using Optical Coherence Tomography: Potential for Staging Cancer

      Imaging of Human Lymph Nodes Using Optical Coherence Tomography: Potential for Staging Cancer
      Histologic assessment is the gold standard technique for the identification of metastatic involvement of lymph nodes in malignant disease, but can only be performed ex vivo and often results in the unnecessary excision of healthy lymph nodes, leading to complications such as lymphedema. Optical coherence tomography (OCT) is a high-resolution, near-IR imaging modality capable of visualizing microscopic features within tissue. OCT has the potential to provide in vivo assessment of tissue involvement by cancer. In this morphologic study, we show the capability of OCT to image nodal microarchitecture through an assessment of fresh, unstained ex vivo lymph node samples. Examples ...
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    11. Intraoperative Evaluation of Breast Tumor Margins with Optical Coherence Tomography

      Intraoperative Evaluation of Breast Tumor Margins with Optical Coherence Tomography
      As breast cancer screening rates increase, smaller and more numerous lesions are being identified earlier, leading to more breast-conserving surgical procedures. Achieving a clean surgical margin represents a technical challenge with important clinical implications. Optical coherence tomography (OCT) is introduced as an intraoperative high-resolution imaging technique that assesses surgical breast tumor margins by providing real-time microscopic images up to 2 mm beneath the tissue surface. In a study of 37 patients split between training and study groups, OCT images covering 1 cm2 regions were acquired from surgical margins of lumpectomy specimens, registered with ink, and correlated with corresponding histologic sections ...
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    12. Vitreo-retinal traction and anastrozole use (OCT & Menopause)

      Background: Menopause is known to increase the risk of vitreo-retinal tractional events such as macular holes and posterior vitreous detachments (PVDs). This suggests that aromatase inhibitors (AIs), which virtually abolish estrogen synthesis in post-menopausal women, may lead to an increased degree of vitreo-retinal traction. To evaluate the hypothesis that AIs lead to heightened vitreo-retinal traction, this study tested the prediction that the foveal shapes of anastrozole users are distorted systematically. Material and Methods: Retinal thickness along the horizontal meridian through the fovea was measured using optical coherence tomography (OCT) for each of 3 groups of amenorrheic women ages 47-69 years ...
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    13. Lymph node micro-architecture can be imaged using optical coherence tomography

      Lymph node micro-architecture can be imaged using optical coherence tomography
      Background: Histological assessment is the gold standard technique for identification of lymph node involvement in breast cancer. However, this may only be performed ex vivo and will often result in the unnecessary excision of healthy lymph nodes. In axillary clearance, this will result in lymphedema in approximately 26% of patients. Optical Coherence Tomography (OCT) is a real-time imaging modality with the potential to perform in vivo optical biopsy of lymph nodes. We undertook ex vivo imaging of excised lymph nodes to identify which aspects of the lymph node micro-architecture could be imaged using OCT, and to identify differences between cancerous ...
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    14. Optical coherence tomography (OCT) as a diagnostic tool for the real-time intraoperative assessment of breast cancer surgical margins.

      Background: The decrease in the number of breast cancer deaths has largely been attributed to increased awareness, earlier detection, and improved treatment options. However, as the number of breast-conserving surgeries rose over the years, the need for negative margins and little or no residual disease has become critical to help reduce the chances of local recurrence. OCT is a high resolution imaging modality that has been used to image tumor margins in an NMU-carcinogen-induced rat mammary tumor model. Due to the location of breast lesions, the use of needle-based imaging probes may be used to further extend the reach of ...
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    15. Interstitial Doppler Optical Coherence Tomography as a Local Tumor Necrosis Predictor in Photodynamic Therapy of Prostatic Carcinoma: An In vivo Study

      We have tested the feasibility of real-time localized blood flow measurements, obtained with interstitial (IS) Doppler optical coherence tomography (DOCT), to predict photodynamic therapy (PDT)-induced tumor necrosis deep within solid Dunning rat prostate tumors. IS-DOCT was used to quantify the PDT-induced microvascular shutdown rate in s.c. Dunning prostate tumors (n = 28). Photofrin (12.5 mg/kg) was administered 20 to 24 hours before tumor irradiation, with 635 nm surface irradiance of 8 to 133 mWcm–2 for 25 minutes. High frequency ultrasound and calipers were used to measure the thickness of the skin covering the tumor and the ...
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    1-15 of 15
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