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Ramella-Roman J, Gandjbakhche AH, Kanick SC, Shadgan B, Tromberg BJ. Special Section Guest Editorial: Wearable, Implantable, Mobile, and Remote Biomedical Optics and Photonics. J Biomed Opt 2021; 26:JBO-21-0617. [PMID: 34189875 PMCID: PMC8241587 DOI: 10.1117/1.jbo.26.6.062701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Accepted: 01/01/2021] [Indexed: 06/13/2023]
Abstract
Guest editors Jessica Ramella-Roman, Amir H. Gandjbakhche, Stephen C. Kanick, Babak Shadgan, and Bruce J. Tromberg introduce and summarize the articles included in the 6-part JBO Special Section on Wearable, Implantable, Mobile, and Remote Biomedical Optics Photonics.
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Affiliation(s)
| | | | | | | | - Bruce J Tromberg
- National Institute of Child Health and Human Development, United States
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Kanick SC, Schneider PA, Klitzman B, Wisniewski NA, Rebrin K. Continuous monitoring of interstitial tissue oxygen using subcutaneous oxygen microsensors: In vivo characterization in healthy volunteers. Microvasc Res 2019; 124:6-18. [PMID: 30742844 PMCID: PMC6570499 DOI: 10.1016/j.mvr.2019.02.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Revised: 02/04/2019] [Accepted: 02/05/2019] [Indexed: 11/19/2022]
Abstract
Measurements of regional tissue oxygen serve as a proxy to monitor local perfusion and have the potential to guide therapeutic decisions in multiple clinical disciplines. Transcutaneous oximetry (tcpO2) is a commercially available noninvasive technique that uses an electrode to warm underlying skin tissue and measure the resulting oxygen tension at the skin surface. A novel approach is to directly measure interstitial tissue oxygen using subcutaneous oxygen microsensors composed of a biocompatible hydrogel carrier platform with embedded oxygen sensing molecules. After initial injection of the hydrogel into subcutaneous tissue, noninvasive optical measurements of phosphorescence-based emissions at the skin surface are used to sense oxygen in the subcutaneous interstitial space. The object of the present study was to characterize the in vivo performance of subcutaneous microsensors and compare with transcutaneous oximetry (tcpO2). Vascular occlusion tests were performed on the arms of 7 healthy volunteers, with repeated tests occurring 1 to 10 weeks after sensor injection, yielding 95 total tests for analysis. Comparative analysis characterized the response of both devices to decreases in tissue oxygen during occlusion and to increases in tissue oxygen following release of the occlusion. Results indicated: (I) time traces returned by microsensors and tcpO2 were highly correlated, with the median (interquartile range) correlation coefficient of r = 0.93 (0.10); (II) both microsensors and tcpO2 sensed a statistically significant decrease in normalized oxygen during occlusion (p < 0.001 for each device); (III) microsensors detected faster rates change (p < 0.001) and detected overshoot during recovery more frequently (38% vs. 4% of tests); (IV) inter-measurement analysis showed no correlation of baseline values between microsensors and tcpO2 (r = 0.03), but comparison of integrated oxygen dynamics showed similar variation in the normalized response to occlusion between devices (p = 0.06), (V) intra-measurement analysis revealed that microsensors detect greater physiological fluctuations than tcpO2 (p < 0.001) and may provide enhanced sensitivity to processes such as vasomotion. Additionally, the functional response of microsensors was not significantly different across time groupings (per month) post-injection (p = 0.61). Although the compared devices have differences in the mechanisms used to sense oxygen, these findings demonstrate that subcutaneous oxygen microsensors measure changes in interstitial tissue oxygen in human subjects in vivo.
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Affiliation(s)
| | | | - Bruce Klitzman
- Kenan Plastic Surgery Research Labs and Biomedical Engineering, Duke University, Durham, NC, USA
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McClatchy DM, Rizzo EJ, Wells WA, Black CC, Paulsen KD, Kanick SC, Pogue BW. Light scattering measured with spatial frequency domain imaging can predict stromal versus epithelial proportions in surgically resected breast tissue. J Biomed Opt 2018; 24:1-11. [PMID: 30264552 PMCID: PMC6676039 DOI: 10.1117/1.jbo.24.7.071605] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 09/04/2018] [Indexed: 05/18/2023]
Abstract
This study aims to determine if light scatter parameters measured with spatial frequency domain imaging (SFDI) can accurately predict stromal, epithelial, and adipose fractions in freshly resected, unstained human breast specimens. An explicit model was developed to predict stromal, epithelial, and adipose fractions as a function of light scattering parameters, which was validated against a quantitative analysis of digitized histology slides for N = 31 specimens using leave-one-out cross-fold validation. Specimen mean stromal, epithelial, and adipose volume fractions predicted from light scattering parameters strongly correlated with those calculated from digitized histology slides (r = 0.90, 0.77, and 0.91, respectively, p-value <1 × 10 - 6). Additionally, the ratio of predicted epithelium to stroma classified malignant specimens with a sensitivity and specificity of 90% and 81%, respectively, and also classified all pixels in malignant lesions with 63% and 79%, at a threshold of 1. All specimens and pixels were classified as malignant, benign, or fat with 84% and 75% accuracy, respectively. These findings demonstrate how light scattering parameters acquired with SFDI can be used to accurately predict and spatially map stromal, epithelial, and adipose proportions in fresh unstained, human breast tissue, and suggest that these estimations could provide diagnostic value.
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Affiliation(s)
- David M. McClatchy
- Dartmouth College, Thayer School of Engineering, Hanover, New Hampshire, United States
- Address all correspondence to: David M. McClatchy, E-mail:
| | - Elizabeth J. Rizzo
- Dartmouth College, Geisel School of Medicine, Department of Pathology, Hanover, New Hampshire, United States
| | - Wendy A. Wells
- Dartmouth College, Geisel School of Medicine, Department of Pathology, Hanover, New Hampshire, United States
- Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, United States
| | - Candice C. Black
- Dartmouth College, Geisel School of Medicine, Department of Pathology, Hanover, New Hampshire, United States
- Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, United States
| | - Keith D. Paulsen
- Dartmouth College, Thayer School of Engineering, Hanover, New Hampshire, United States
- Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, United States
| | - Stephen C. Kanick
- Dartmouth College, Thayer School of Engineering, Hanover, New Hampshire, United States
| | - Brian W. Pogue
- Dartmouth College, Thayer School of Engineering, Hanover, New Hampshire, United States
- Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, United States
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Roberts DW, Olson JD, Evans LT, Kolste KK, Kanick SC, Fan X, Bravo JJ, Wilson BC, Leblond F, Marois M, Paulsen KD. Red-light excitation of protoporphyrin IX fluorescence for subsurface tumor detection. J Neurosurg 2018; 128:1690-1697. [PMID: 28777025 PMCID: PMC5797501 DOI: 10.3171/2017.1.jns162061] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
OBJECTIVE The objective of this study was to detect 5-aminolevulinic acid (ALA)-induced tumor fluorescence from glioma below the surface of the surgical field by using red-light illumination. METHODS To overcome the shallow tissue penetration of blue light, which maximally excites the ALA-induced fluorophore protoporphyrin IX (PpIX) but is also strongly absorbed by hemoglobin and oxyhemoglobin, a system was developed to illuminate the surgical field with red light (620-640 nm) matching a secondary, smaller absorption peak of PpIX and detecting the fluorescence emission through a 650-nm longpass filter. This wide-field spectroscopic imaging system was used in conjunction with conventional blue-light fluorescence for comparison in 29 patients undergoing craniotomy for resection of high-grade glioma, low-grade glioma, meningioma, or metastasis. RESULTS Although, as expected, red-light excitation is less sensitive to PpIX in exposed tumor, it did reveal tumor at a depth up to 5 mm below the resection bed in 22 of 24 patients who also exhibited PpIX fluorescence under blue-light excitation during the course of surgery. CONCLUSIONS Red-light excitation of tumor-associated PpIX fluorescence below the surface of the surgical field can be achieved intraoperatively and enables detection of subsurface tumor that is not visualized under conventional blue-light excitation. Clinical trial registration no.: NCT02191488 (clinicaltrials.gov).
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Affiliation(s)
- David W. Roberts
- Section of Neurosurgery, Dartmouth-Hitchcock Medical Center, Lebanon
- Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire
- Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
| | - Jonathan D. Olson
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
| | - Linton T. Evans
- Section of Neurosurgery, Dartmouth-Hitchcock Medical Center, Lebanon
| | - Kolbein K. Kolste
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
| | - Stephen C. Kanick
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
| | - Xiaoyao Fan
- Section of Neurosurgery, Dartmouth-Hitchcock Medical Center, Lebanon
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
| | - Jaime J. Bravo
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
| | - Brian C. Wilson
- Princess Margaret Cancer Centre/University Health Network and Department of Medical Biophysics, University of Toronto, Ontario
| | - Frederic Leblond
- Department of Engineering Physics, Polytechnique Montreal, Quebec
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal, Quebec, Canada
| | - Mikael Marois
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
| | - Keith D. Paulsen
- Section of Neurosurgery, Dartmouth-Hitchcock Medical Center, Lebanon
- Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
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Carlson ML, McClatchy DM, Gunn JR, Elliott JT, Paulsen KD, Kanick SC, Pogue BW. Wide-field color imaging of scatter-based tissue contrast using both high spatial frequency illumination and cross-polarization gating. J Biophotonics 2018. [PMID: 29024450 DOI: 10.1002/jbio.2018.11.issue-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
This study characterizes the scatter-specific tissue contrast that can be obtained by high spatial frequency (HSF) domain imaging and cross-polarization (CP) imaging, using a standard color imaging system, and how combining them may be beneficial. Both HSF and CP approaches are known to modulate the sensitivity of epi-illumination reflectance images between diffuse multiply scattered and superficially backscattered photons, providing enhanced contrast from microstructure and composition than what is achieved by standard wide-field imaging. Measurements in tissue-simulating optical phantoms show that CP imaging returns localized assessments of both scattering and absorption effects, while HSF has uniquely specific sensitivity to scatter-only contrast, with a strong suppression of visible contrast from blood. The combination of CP and HSF imaging provided an expanded sensitivity to scatter compared with CP imaging, while rejecting specular reflections detected by HSF imaging. ex vivo imaging of an atlas of dissected rodent organs/tissues demonstrated the scatter-based contrast achieved with HSF, CP and HSF-CP imaging, with the white light spectral signal returned by each approach translated to a color image for intuitive encoding of scatter-based contrast within images of tissue. The results suggest that visible CP-HSF imaging could have the potential to aid diagnostic imaging of lesions in skin or mucosal tissues and organs, where just CP is currently the standard practice imaging modality.
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Affiliation(s)
| | - David M McClatchy
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
| | - Jason R Gunn
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
| | - Jonathan T Elliott
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
- Norris Cotton Cancer Center, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire
| | - Keith D Paulsen
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
- Norris Cotton Cancer Center, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire
| | - Stephen C Kanick
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
- Norris Cotton Cancer Center, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire
- Profusa, Inc., South San Francisco, California
| | - Brian W Pogue
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
- Norris Cotton Cancer Center, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire
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Carlson ML, McClatchy DM, Gunn JR, Elliott JT, Paulsen KD, Kanick SC, Pogue BW. Wide-field color imaging of scatter-based tissue contrast using both high spatial frequency illumination and cross-polarization gating. J Biophotonics 2018; 11:e201700104. [PMID: 28800205 DOI: 10.1002/jbio.201700104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 07/13/2017] [Accepted: 07/14/2017] [Indexed: 06/07/2023]
Abstract
This study characterizes the scatter-specific tissue contrast that can be obtained by high spatial frequency (HSF) domain imaging and cross-polarization (CP) imaging, using a standard color imaging system, and how combining them may be beneficial. Both HSF and CP approaches are known to modulate the sensitivity of epi-illumination reflectance images between diffuse multiply scattered and superficially backscattered photons, providing enhanced contrast from microstructure and composition than what is achieved by standard wide-field imaging. Measurements in tissue-simulating optical phantoms show that CP imaging returns localized assessments of both scattering and absorption effects, while HSF has uniquely specific sensitivity to scatter-only contrast, with a strong suppression of visible contrast from blood. The combination of CP and HSF imaging provided an expanded sensitivity to scatter compared with CP imaging, while rejecting specular reflections detected by HSF imaging. ex vivo imaging of an atlas of dissected rodent organs/tissues demonstrated the scatter-based contrast achieved with HSF, CP and HSF-CP imaging, with the white light spectral signal returned by each approach translated to a color image for intuitive encoding of scatter-based contrast within images of tissue. The results suggest that visible CP-HSF imaging could have the potential to aid diagnostic imaging of lesions in skin or mucosal tissues and organs, where just CP is currently the standard practice imaging modality.
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Affiliation(s)
| | - David M McClatchy
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
| | - Jason R Gunn
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
| | - Jonathan T Elliott
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
- Norris Cotton Cancer Center, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire
| | - Keith D Paulsen
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
- Norris Cotton Cancer Center, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire
| | - Stephen C Kanick
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
- Norris Cotton Cancer Center, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire
- Profusa, Inc., South San Francisco, California
| | - Brian W Pogue
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
- Norris Cotton Cancer Center, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire
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Nieskoski MD, Marra K, Gunn JR, Kanick SC, Doyley MM, Hasan T, Pereira SP, Stuart Trembly B, Pogue BW. Separation of Solid Stress From Interstitial Fluid Pressure in Pancreas Cancer Correlates With Collagen Area Fraction. J Biomech Eng 2017; 139:2618331. [PMID: 28388715 PMCID: PMC6993781 DOI: 10.1115/1.4036392] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 03/03/2017] [Indexed: 12/12/2022]
Abstract
Elevated total tissue pressure (TTP) in pancreatic adenocarcinoma is often associated with stress applied by cellular proliferation and hydrated hyaluronic acid osmotic swelling; however, the causal roles of collagen in total tissue pressure have yet to be clearly measured. This study illustrates one direct correlation between total tissue pressure and increased deposition of collagen within the tissue matrix. This observation comes from a new modification to a conventional piezoelectric pressure catheter, used to independently separate and quantify total tissue pressure, solid stress (SS), and interstitial fluid pressure (IFP) within the same tumor location, thereby clarifying the relationship between these parameters. Additionally, total tissue pressure shows a direct correlation with verteporfin uptake, demonstrating the impediment of systemically delivered molecules with increased tissue hypertension.
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Affiliation(s)
| | - Kayla Marra
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755
| | - Jason R Gunn
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755
| | - Stephen C Kanick
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755
| | - Marvin M Doyley
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755;Department of Electrical and Computer Engineering, University of Rochester, Rochester, NY 14627
| | - Tayyaba Hasan
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114
| | - Stephen P Pereira
- Institute for Liver and Digestive Health, University College London, London NW3 2QG, UK
| | - B Stuart Trembly
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755
| | - Brian W Pogue
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755 e-mail:
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Thatcher JE, Squiers JJ, Kanick SC, King DR, Lu Y, Wang Y, Mohan R, Sellke EW, DiMaio JM. Imaging Techniques for Clinical Burn Assessment with a Focus on Multispectral Imaging. Adv Wound Care (New Rochelle) 2016; 5:360-378. [PMID: 27602255 DOI: 10.1089/wound.2015.0684] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Accepted: 03/16/2016] [Indexed: 11/13/2022] Open
Abstract
Significance: Burn assessments, including extent and severity, are some of the most critical diagnoses in burn care, and many recently developed imaging techniques may have the potential to improve the accuracy of these evaluations. Recent Advances: Optical devices, telemedicine, and high-frequency ultrasound are among the highlights in recent burn imaging advancements. We present another promising technology, multispectral imaging (MSI), which also has the potential to impact current medical practice in burn care, among a variety of other specialties. Critical Issues: At this time, it is still a matter of debate as to why there is no consensus on the use of technology to assist burn assessments in the United States. Fortunately, the availability of techniques does not appear to be a limitation. However, the selection of appropriate imaging technology to augment the provision of burn care can be difficult for clinicians to navigate. There are many technologies available, but a comprehensive review summarizing the tissue characteristics measured by each technology in light of aiding clinicians in selecting the proper device is missing. This would be especially valuable for the nonburn specialists who encounter burn injuries. Future Directions: The questions of when burn assessment devices are useful to the burn team, how the various imaging devices work, and where the various burn imaging technologies fit into the spectrum of burn care will continue to be addressed. Technologies that can image a large surface area quickly, such as thermography or laser speckle imaging, may be suitable for initial burn assessment and triage. In the setting of presurgical planning, ultrasound or optical microscopy techniques, including optical coherence tomography, may prove useful. MSI, which actually has origins in burn care, may ultimately meet a high number of requirements for burn assessment in routine clinical use.
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Affiliation(s)
| | - John J. Squiers
- Spectral MD, Inc., Dallas, Texas
- Baylor Research Institute, Baylor Scott & White Health, Dallas, Texas
| | | | | | - Yang Lu
- Spectral MD, Inc., Dallas, Texas
| | | | | | | | - J. Michael DiMaio
- Spectral MD, Inc., Dallas, Texas
- Baylor Research Institute, Baylor Scott & White Health, Dallas, Texas
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Bravo JJ, Davis SC, Roberts DW, Paulsen KD, Kanick SC. Mathematical model to interpret localized reflectance spectra measured in the presence of a strong fluorescence marker. J Biomed Opt 2016; 21:61004. [PMID: 26836297 PMCID: PMC4734982 DOI: 10.1117/1.jbo.21.6.061004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 12/31/2015] [Indexed: 06/05/2023]
Abstract
Quantification of multiple fluorescence markers during neurosurgery has the potential to provide complementary contrast mechanisms between normal and malignant tissues, and one potential combination involves fluorescein sodium (FS) and aminolevulinic acid-induced protoporphyrin IX (PpIX). We focus on the interpretation of reflectance spectra containing contributions from elastically scattered (reflected) photons as well as fluorescence emissions from a strong fluorophore (i.e., FS). A model-based approach to extract μa and μ′s in the presence of FS emission is validated in optical phantoms constructed with Intralipid (1% to 2% lipid) and whole blood (1% to 3% volume fraction), over a wide range of FS concentrations (0 to 1000 μg/ml 1000 μg/ml ). The results show that modeling reflectance as a combination of elastically scattered light and attenuation-corrected FS-based emission yielded more accurate tissue parameter estimates when compared with a nonmodified reflectance model, with reduced maximum errors for blood volume (22% versus 90%), microvascular saturation (21% versus 100%), and μs′ (13% versus 207%). Additionally, quantitative PpIX fluorescence sampled in the same phantom as FS showed significant differences depending on the reflectance model used to estimate optical properties (i.e., maximum error 29% versus 86%). These data represent a first step toward using quantitative optical spectroscopy to guide surgeries through simultaneous assessment of FS and PpIX.
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Affiliation(s)
- Jaime J. Bravo
- Dartmouth College, Thayer School of Engineering, 14 Engineering Drive, Hanover, New Hampshire 03755, United States
| | - Scott C. Davis
- Dartmouth College, Thayer School of Engineering, 14 Engineering Drive, Hanover, New Hampshire 03755, United States
- Dartmouth-Hitchcock Medical Center, Norris Cotton Cancer Center, 1 Medical Center Drive, Lebanon, New Hampshire 03756, United States
| | - David W. Roberts
- Dartmouth-Hitchcock Medical Center, Norris Cotton Cancer Center, 1 Medical Center Drive, Lebanon, New Hampshire 03756, United States
- Geisel School of Medicine at Dartmouth, 1 Rope Ferry Road, Hanover, New Hampshire 03755, United States
- Dartmouth-Hitchcock Medical Center, Section of Neurosurgery, 1 Medical Center Drive, Lebanon, New Hampshire 03756, United States
| | - Keith D. Paulsen
- Dartmouth College, Thayer School of Engineering, 14 Engineering Drive, Hanover, New Hampshire 03755, United States
- Dartmouth-Hitchcock Medical Center, Norris Cotton Cancer Center, 1 Medical Center Drive, Lebanon, New Hampshire 03756, United States
- Geisel School of Medicine at Dartmouth, 1 Rope Ferry Road, Hanover, New Hampshire 03755, United States
| | - Stephen C. Kanick
- Dartmouth College, Thayer School of Engineering, 14 Engineering Drive, Hanover, New Hampshire 03755, United States
- Dartmouth-Hitchcock Medical Center, Norris Cotton Cancer Center, 1 Medical Center Drive, Lebanon, New Hampshire 03756, United States
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Pogue BW, Elliott JT, Kanick SC, Davis SC, Samkoe KS, Maytin EV, Pereira SP, Hasan T. Revisiting photodynamic therapy dosimetry: reductionist & surrogate approaches to facilitate clinical success. Phys Med Biol 2016; 61:R57-89. [PMID: 26961864 DOI: 10.1088/0031-9155/61/7/r57] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Photodynamic therapy (PDT) can be a highly complex treatment, with many parameters influencing treatment efficacy. The extent to which dosimetry is used to monitor and standardize treatment delivery varies widely, ranging from measurement of a single surrogate marker to comprehensive approaches that aim to measure or estimate as many relevant parameters as possible. Today, most clinical PDT treatments are still administered with little more than application of a prescribed drug dose and timed light delivery, and thus the role of patient-specific dosimetry has not reached widespread clinical adoption. This disconnect is at least partly due to the inherent conflict between the need to measure and understand multiple parameters in vivo in order to optimize treatment, and the need for expedience in the clinic and in the regulatory and commercialization process. Thus, a methodical approach to selecting primary dosimetry metrics is required at each stage of translation of a treatment procedure, moving from complex measurements to understand PDT mechanisms in pre-clinical and early phase I trials, towards the identification and application of essential dose-limiting and/or surrogate measurements in phase II/III trials. If successful, identifying the essential and/or reliable surrogate dosimetry measurements should help facilitate increased adoption of clinical PDT. In this paper, examples of essential dosimetry points and surrogate dosimetry tools that may be implemented in phase II/III trials are discussed. For example, the treatment efficacy as limited by light penetration in interstitial PDT may be predicted by the amount of contrast uptake in CT, and so this could be utilized as a surrogate dosimetry measurement to prescribe light doses based upon pre-treatment contrast. Success of clinical ALA-based skin lesion treatment is predicted almost uniquely by the explicit or implicit measurements of photosensitizer and photobleaching, yet the individualization of treatment based upon each patients measured bleaching needs to be attempted. In the case of ALA, lack of PpIX is more likely an indicator that alternative PpIX production methods must be implemented. Parsimonious dosimetry, using surrogate measurements that are clinically acceptable, might strategically help to advance PDT in a medical world that is increasingly cost and time sensitive. Careful attention to methodologies that can identify and advance the most critical dosimetric measurements, either direct or surrogate, are needed to ensure successful incorporation of PDT into niche clinical procedures.
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Affiliation(s)
- Brian W Pogue
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA. Department of Surgery, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
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Bravo JJ, Paulsen KD, Roberts DW, Kanick SC. Sub-diffuse optical biomarkers characterize localized microstructure and function of cortex and malignant tumor. Opt Lett 2016; 41:781-4. [PMID: 26872187 PMCID: PMC4769594 DOI: 10.1364/ol.41.000781] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
This study uses a sub-diffusive light transport model to analyze fiber-optic measurements of reflectance spectra to recover endogenous tissue biomarkers and to correct raw fluorescence emissions for distortions from background optical properties. Measurements in tissue-simulating phantoms validated accurate recovery of the reduced scattering coefficient [(0.3-3.4 mm-1), error 10%], blood volume fraction [(1-3 vol%), error 7%], and a dimensionless metric of anisotropic scattering, γ, that is sensitive to submillimeter tissue ultrastructure [(1.29-2.06), error 11%]. In vivo sub-diffusive optical data acquired during clinical neurosurgeries characterize differences in microstructure (γ), perfusion (blood volume), and metabolism (PpIX fluorescence) between normal cortex and malignant tumor.
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Affiliation(s)
- Jaime J. Bravo
- Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, New Hampshire 03755, USA
| | - Keith D. Paulsen
- Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, New Hampshire 03755, USA
- Department of Neurosurgery, Dartmouth Hitchcock Medical Center, 1 Medical Center Dr., Bldg. 50, Lebanon, New Hampshire 03766, USA
- Norris Cotton Cancer Center, Dartmouth Hitchcock Medical Center, 1 Medical Center Dr., Bldg. 50, Lebanon, New Hampshire 03766, USA
| | - David W. Roberts
- Department of Neurosurgery, Dartmouth Hitchcock Medical Center, 1 Medical Center Dr., Bldg. 50, Lebanon, New Hampshire 03766, USA
- Norris Cotton Cancer Center, Dartmouth Hitchcock Medical Center, 1 Medical Center Dr., Bldg. 50, Lebanon, New Hampshire 03766, USA
| | - Stephen C. Kanick
- Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, New Hampshire 03755, USA
- Norris Cotton Cancer Center, Dartmouth Hitchcock Medical Center, 1 Medical Center Dr., Bldg. 50, Lebanon, New Hampshire 03766, USA
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Kanick SC, Davis SC, Zhao Y, Sheehan KL, Hasan T, Maytin EV, Pogue BW, Chapman MS. Pre-treatment protoporphyrin IX concentration in actinic keratosis lesions may be a predictive biomarker of response to aminolevulinic-acid based photodynamic therapy. Photodiagnosis Photodyn Ther 2015; 12:561-6. [PMID: 26480810 DOI: 10.1016/j.pdpdt.2015.10.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Revised: 09/14/2015] [Accepted: 10/12/2015] [Indexed: 01/23/2023]
Abstract
BACKGROUND Although aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) photodynamic therapy (PDT) is an effective FDA-approved therapy for actinic keratosis (AK), a substantial fraction of patients (up to 25%) do not respond to treatment. This study examined the feasibility of using pre-treatment measurements of PpIX concentration in AK lesions to predict response of ALA-PpIX PDT. METHODS A non-invasive fiber-optic fluorescence spectroscopy system was used to measure PpIX concentration in patients undergoing standard-of-care ALA-PDT for AK. All patients provided assessments of pain at the time of treatment (n=70), and a subset reported pain and erythema 48-76 h after treatment (n=13). RESULTS PpIX concentration was significantly higher in lesions of patients reporting high levels of pain (VAS score ≥5) immediately after treatment vs. patients reporting pain scores below VAS=5 (p<0.022) (n=70). However, pain was not an exclusive indicator of PpIX concentration as many patients with low PpIX concentration reported high pain. In a subpopulation of patients surveyed in the days after treatment (n=13), PpIX concentration measured on the day of treatment was uncorrelated with pain-reported immediately after treatment (r=0.17, p<0.57), but positive correlations were found between PpIX concentration and patient-reported pain (r=0.55, p<0.051) and erythema (r=0.58, p<0.039) in the 48-72 h following treatment. CONCLUSIONS These data suggest that in vivo optical measurements of PpIX concentration acquired before light delivery may be an objective predictor of response to ALA-PpIX PDT. Identification of non-responding patients on the day of treatment could facilitate the use of interventions that may improve outcomes.
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Affiliation(s)
- S C Kanick
- Thayer School of Engineering, Dartmouth College, Hanover, USA; Norris Cotton Cancer Center, Dartmouth Hitchcock Medical Center, Lebanon NH, USA.
| | - S C Davis
- Thayer School of Engineering, Dartmouth College, Hanover, USA; Norris Cotton Cancer Center, Dartmouth Hitchcock Medical Center, Lebanon NH, USA
| | - Y Zhao
- Thayer School of Engineering, Dartmouth College, Hanover, USA
| | - K L Sheehan
- Department of Surgery, Dartmouth Hitchcock Medical Center, Lebanon, USA
| | - T Hasan
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, USA
| | - E V Maytin
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, USA; Biomedical Engineering, Cleveland Clinic, Cleveland, USA
| | - B W Pogue
- Thayer School of Engineering, Dartmouth College, Hanover, USA; Norris Cotton Cancer Center, Dartmouth Hitchcock Medical Center, Lebanon NH, USA; Department of Surgery, Dartmouth Hitchcock Medical Center, Lebanon, USA; Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, USA
| | - M S Chapman
- Department of Surgery, Dartmouth Hitchcock Medical Center, Lebanon, USA
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13
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McClatchy DM, Krishnaswamy V, Kanick SC, Elliott JT, Wells WA, Barth RJ, Paulsen KD, Pogue BW. Molecular dyes used for surgical specimen margin orientation allow for intraoperative optical assessment during breast conserving surgery. J Biomed Opt 2015; 20:040504. [PMID: 25901654 PMCID: PMC4406078 DOI: 10.1117/1.jbo.20.4.040504] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 03/31/2015] [Indexed: 05/23/2023]
Abstract
A variety of optical techniques utilizing near-infrared (NIR) light are being proposed for intraoperative breast tumor margin assessment. However, immediately following a lumpectomy excision, the margins are inked, which preserves the orientation of the specimen but prevents optical interrogation of the tissue margins. Here, a workflow is proposed that allows for both NIR optical assessment following full specimen marking using molecular dyes which have negligible absorption and scattering in the NIR. The effect of standard surgical inks in contrast to molecular dyes for an NIR signal is shown. Further, the proposed workflow is demonstrated with full specimen intraoperative imaging on all margins directly after the lumpectomy has been excised and completely marked. This work is an important step in the path to clinical feasibility of intraoperative breast tumor margin assessment using NIR optical methods without having to compromise on the current clinical practice of inking resected specimens for margin orientation.
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Affiliation(s)
- David M. McClatchy
- Dartmouth College, Thayer School of Engineering, 14 Engineering Drive, Hanover, New Hampshire 03755, United States
| | - Venkataramanan Krishnaswamy
- Dartmouth College, Thayer School of Engineering, 14 Engineering Drive, Hanover, New Hampshire 03755, United States
| | - Stephen C. Kanick
- Dartmouth College, Thayer School of Engineering, 14 Engineering Drive, Hanover, New Hampshire 03755, United States
| | - Jonathan T. Elliott
- Dartmouth College, Thayer School of Engineering, 14 Engineering Drive, Hanover, New Hampshire 03755, United States
| | - Wendy A. Wells
- Dartmouth College, Department of Pathology, Geisel School of Medicine, 1 Rope Ferry Road, Hanover, New Hampshire 03755, United States
| | - Richard J. Barth
- Dartmouth College, Department of Surgery, Geisel School of Medicine, 1 Rope Ferry Road, Hanover, New Hampshire 03755, United States
| | - Keith D. Paulsen
- Dartmouth College, Thayer School of Engineering, 14 Engineering Drive, Hanover, New Hampshire 03755, United States
- Dartmouth College, Department of Diagnostic Radiology, Geisel School of Medicine, 1 Rope Ferry Road, Hanover, New Hampshire 03755, United States
| | - Brian W. Pogue
- Dartmouth College, Thayer School of Engineering, 14 Engineering Drive, Hanover, New Hampshire 03755, United States
- Dartmouth College, Department of Surgery, Geisel School of Medicine, 1 Rope Ferry Road, Hanover, New Hampshire 03755, United States
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14
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McClatchy DM, Krishnaswamy V, Kanick SC, Elliott JT, Wells WA, Barth RJ, Paulsen KD, Pogue BW. High spatial frequency structured light imaging for intraoperative breast tumor margin assessment. ACTA ACUST UNITED AC 2015. [DOI: 10.1117/12.2080134] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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15
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Kolste KK, Kanick SC, Valdés PA, Jermyn M, Wilson BC, Roberts DW, Paulsen KD, Leblond F. Macroscopic optical imaging technique for wide-field estimation of fluorescence depth in optically turbid media for application in brain tumor surgical guidance. J Biomed Opt 2015; 20:26002. [PMID: 25652704 PMCID: PMC4405086 DOI: 10.1117/1.jbo.20.2.026002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 01/05/2015] [Indexed: 05/13/2023]
Abstract
A diffuse imaging method is presented that enables wide-field estimation of the depth of fluorescent molecular markers in turbid media by quantifying the deformation of the detected fluorescence spectra due to the wavelength-dependent light attenuation by overlying tissue. This is achieved by measuring the ratio of the fluorescence at two wavelengths in combination with normalization techniques based on diffuse reflectance measurements to evaluate tissue attenuation variations for different depths. It is demonstrated that fluorescence topography can be achieved up to a 5 mm depth using a near-infrared dye with millimeter depth accuracy in turbid media having optical properties representative of normal brain tissue. Wide-field depth estimates are made using optical technology integrated onto a commercial surgical microscope, making this approach feasible for real-world applications.
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Affiliation(s)
- Kolbein K. Kolste
- Dartmouth College, Thayer School of Engineering, Hanover, 14 Engineering Drive, New Hampshire 03755, United States
| | - Stephen C. Kanick
- Dartmouth College, Thayer School of Engineering, Hanover, 14 Engineering Drive, New Hampshire 03755, United States
| | - Pablo A. Valdés
- Dartmouth College, Thayer School of Engineering, Hanover, 14 Engineering Drive, New Hampshire 03755, United States
- Dartmouth College, Geisel School of Medicine, Hanover, 1 Rope Ferry Road, New Hampshire 03755, United States
| | - Michael Jermyn
- Polytechnique Montreal, Engineering Physics Department, Montreal, Québec H3C 3A7, Canada
| | - Brian C. Wilson
- University of Toronto, Ontario Cancer Institute, 610 University Avenue, Toronto, Ontario M5G 2M9, Canada
| | - David W. Roberts
- Dartmouth-Hitchcock Medical Center, Section of Neurosurgery, 1 Medical Center Drive, Lebanon, New Hampshire 03756, United States
| | - Keith D. Paulsen
- Dartmouth College, Thayer School of Engineering, Hanover, 14 Engineering Drive, New Hampshire 03755, United States
| | - Frederic Leblond
- Polytechnique Montreal, Engineering Physics Department, Montreal, Québec H3C 3A7, Canada
- Address all correspondence to: Frederic Leblond, E-mail:
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16
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Kanick SC, Tichauer KM, Gunn J, Samkoe KS, Pogue BW. Pixel-based absorption correction for dual-tracer fluorescence imaging of receptor binding potential. Biomed Opt Express 2014; 5:3280-91. [PMID: 25360349 PMCID: PMC4206301 DOI: 10.1364/boe.5.003280] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 08/21/2014] [Accepted: 08/23/2014] [Indexed: 05/07/2023]
Abstract
Ratiometric approaches to quantifying molecular concentrations have been used for decades in microscopy, but have rarely been exploited in vivo until recently. One dual-tracer approach can utilize an untargeted reference tracer to account for non-specific uptake of a receptor-targeted tracer, and ultimately estimate receptor binding potential quantitatively. However, interpretation of the relative dynamic distribution kinetics is confounded by differences in local tissue absorption at the wavelengths used for each tracer. This study simulated the influence of absorption on fluorescence emission intensity and depth sensitivity at typical near-infrared fluorophore wavelength bands near 700 and 800 nm in mouse skin in order to correct for these tissue optical differences in signal detection. Changes in blood volume [1-3%] and hemoglobin oxygen saturation [0-100%] were demonstrated to introduce substantial distortions to receptor binding estimates (error > 30%), whereas sampled depth was relatively insensitive to wavelength (error < 6%). In response, a pixel-by-pixel normalization of tracer inputs immediately post-injection was found to account for spatial heterogeneities in local absorption properties. Application of the pixel-based normalization method to an in vivo imaging study demonstrated significant improvement, as compared with a reference tissue normalization approach.
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Affiliation(s)
- Stephen C. Kanick
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755, USA
| | - Kenneth M. Tichauer
- Department of Biomedical Engineering, Illinois Institute of Technology, Chicago IL 60616, USA
| | - Jason Gunn
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755, USA
| | - Kimberley S. Samkoe
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755, USA
- Department of Surgery, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755, USA
| | - Brian W. Pogue
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755, USA
- Department of Surgery, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755, USA
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17
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Sexton K, Davis SC, McClatchy D, Valdes PA, Kanick SC, Paulsen KD, Roberts DW, Pogue BW. Pulsed-light imaging for fluorescence guided surgery under normal room lighting. Opt Lett 2013; 38:3249-52. [PMID: 23988926 PMCID: PMC4051311 DOI: 10.1364/ol.38.003249] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Fluorescence guided surgery (FGS) is an emerging technology that has demonstrated improved surgical outcomes. However, dim lighting conditions required by current FGS systems are disruptive to standard surgical workflow. We present a novel FGS system capable of imaging fluorescence under normal room light by using pulsed excitation and gated acquisition. Images from tissue-simulating phantoms confirm visual detection down to 0.25 μM of protoporphyrin IX under 125 μW/cm2 of ambient light, more than an order of magnitude lower than that measured with the Zeiss Pentero in the dark. Resection of orthotopic brain tumors in mice also suggests that the pulsed-light system provides superior sensitivity in vivo.
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Affiliation(s)
- Kristian Sexton
- Thayer School of Engineering at Dartmouth College, 14 Engineering Dr. Hanover, New Hampshire 03755, USA
- Corresponding author:
| | - Scott C. Davis
- Thayer School of Engineering at Dartmouth College, 14 Engineering Dr. Hanover, New Hampshire 03755, USA
| | - David McClatchy
- Thayer School of Engineering at Dartmouth College, 14 Engineering Dr. Hanover, New Hampshire 03755, USA
| | - Pablo A. Valdes
- Thayer School of Engineering at Dartmouth College, 14 Engineering Dr. Hanover, New Hampshire 03755, USA
- Geisel School of Medicine at Dartmouth College, 1 Rope Ferry Drive, Hanover, New Hampshire 03755, USA
- Section of Neurosurgery, Dartmouth-Hitchcock Medical Center, 1 Medical Center Drive, Lebanon, New Hampshire 03756, USA
| | - Stephen C. Kanick
- Thayer School of Engineering at Dartmouth College, 14 Engineering Dr. Hanover, New Hampshire 03755, USA
| | - Keith D. Paulsen
- Thayer School of Engineering at Dartmouth College, 14 Engineering Dr. Hanover, New Hampshire 03755, USA
- Geisel School of Medicine at Dartmouth College, 1 Rope Ferry Drive, Hanover, New Hampshire 03755, USA
| | - David W. Roberts
- Geisel School of Medicine at Dartmouth College, 1 Rope Ferry Drive, Hanover, New Hampshire 03755, USA
- Section of Neurosurgery, Dartmouth-Hitchcock Medical Center, 1 Medical Center Drive, Lebanon, New Hampshire 03756, USA
| | - Brian W. Pogue
- Thayer School of Engineering at Dartmouth College, 14 Engineering Dr. Hanover, New Hampshire 03755, USA
- Geisel School of Medicine at Dartmouth College, 1 Rope Ferry Drive, Hanover, New Hampshire 03755, USA
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18
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Glaser AK, Kanick SC, Zhang R, Arce P, Pogue BW. A GAMOS plug-in for GEANT4 based Monte Carlo simulation of radiation-induced light transport in biological media. Biomed Opt Express 2013; 4:741-59. [PMID: 23667790 PMCID: PMC3646601 DOI: 10.1364/boe.4.000741] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Revised: 04/03/2013] [Accepted: 04/09/2013] [Indexed: 05/20/2023]
Abstract
We describe a tissue optics plug-in that interfaces with the GEANT4/GAMOS Monte Carlo (MC) architecture, providing a means of simulating radiation-induced light transport in biological media for the first time. Specifically, we focus on the simulation of light transport due to the Čerenkov effect (light emission from charged particle's traveling faster than the local speed of light in a given medium), a phenomenon which requires accurate modeling of both the high energy particle and subsequent optical photon transport, a dynamic coupled process that is not well-described by any current MC framework. The results of validation simulations show excellent agreement with currently employed biomedical optics MC codes, [i.e., Monte Carlo for Multi-Layered media (MCML), Mesh-based Monte Carlo (MMC), and diffusion theory], and examples relevant to recent studies into detection of Čerenkov light from an external radiation beam or radionuclide are presented. While the work presented within this paper focuses on radiation-induced light transport, the core features and robust flexibility of the plug-in modified package make it also extensible to more conventional biomedical optics simulations. The plug-in, user guide, example files, as well as the necessary files to reproduce the validation simulations described within this paper are available online at http://www.dartmouth.edu/optmed/research-projects/monte-carlo-software.
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Affiliation(s)
- Adam K. Glaser
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755, USA
| | - Stephen C. Kanick
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755, USA
| | - Rongxiao Zhang
- Department of Physics and Astronomy, Dartmouth College, Hanover, New Hampshire 03755, USA
| | - Pedro Arce
- CIEMAT (Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas), Madrid, Spain
| | - Brian W. Pogue
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755, USA
- Department of Physics and Astronomy, Dartmouth College, Hanover, New Hampshire 03755, USA
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19
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Flynn BP, DSouza AV, Kanick SC, Davis SC, Pogue BW. White light-informed optical properties improve ultrasound-guided fluorescence tomography of photoactive protoporphyrin IX. J Biomed Opt 2013; 18:046008. [PMID: 23584445 PMCID: PMC3639786 DOI: 10.1117/1.jbo.18.4.046008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Subsurface fluorescence imaging is desirable for medical applications, including protoporphyrin-IX (PpIX)-based skin tumor diagnosis, surgical guidance, and dosimetry in photodynamic therapy. While tissue optical properties and heterogeneities make true subsurface fluorescence mapping an ill-posed problem, ultrasound-guided fluorescence-tomography (USFT) provides regional fluorescence mapping. Here USFT is implemented with spectroscopic decoupling of fluorescence signals (auto-fluorescence, PpIX, photoproducts), and white light spectroscopy-determined bulk optical properties. Segmented US images provide a priori spatial information for fluorescence reconstruction using region-based, diffuse FT. The method was tested in simulations, tissue homogeneous and inclusion phantoms, and an injected-inclusion animal model. Reconstructed fluorescence yield was linear with PpIX concentration, including the lowest concentration used, 0.025 μg/ml. White light spectroscopy informed optical properties, which improved fluorescence reconstruction accuracy compared to the use of fixed, literature-based optical properties, reduced reconstruction error and reconstructed fluorescence standard deviation by factors of 8.9 and 2.0, respectively. Recovered contrast-to-background error was 25% and 74% for inclusion phantoms without and with a 2-mm skin-like layer, respectively. Preliminary mouse-model imaging demonstrated system feasibility for subsurface fluorescence measurement in vivo. These data suggest that this implementation of USFT is capable of regional PpIX mapping in human skin tumors during photodynamic therapy, to be used in dosimetric evaluations.
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Affiliation(s)
- Brendan P. Flynn
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755
| | - Alisha V. DSouza
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755
| | - Stephen C. Kanick
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755
| | - Scott C. Davis
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755
| | - Brian W. Pogue
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755
- Address all correspondence to: Brian W. Pogue, Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755. Tel: (603) 646-3861; E-mail:
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20
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Rollakanti KR, Kanick SC, Davis SC, Pogue BW, Maytin EV. Techniques for fluorescence detection of protoporphyrin IX in skin cancers associated with photodynamic therapy. ACTA ACUST UNITED AC 2013; 2:287-303. [PMID: 25599015 DOI: 10.1515/plm-2013-0030] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Photodynamic therapy (PDT) is a treatment modality that uses a specific photosensitizing agent, molecular oxygen, and light of a particular wavelength to kill cells targeted by the therapy. Topically administered aminolevulinic acid (ALA) is widely used to effectively treat cancerous and precancerous skin lesions, resulting in targeted tissue damage and little to no scarring. The targeting aspect of the treatment arises from the fact that ALA is preferentially converted into protoporphyrin IX (PpIX) in neoplastic cells. To monitor the amount of PpIX in tissues, techniques have been developed to measure PpIX-specific fluorescence, which provides information useful for monitoring the abundance and location of the photosensitizer before and during the illumination phase of PDT. This review summarizes the current state of these fluorescence detection techniques. Non-invasive devices are available for point measurements, or for wide-field optical imaging, to enable monitoring of PpIX in superficial tissues. To gain access to information at greater tissue depths, multi-modal techniques are being developed which combine fluorescent measurements with ultrasound or optical coherence tomography, or with microscopic techniques such as confocal or multiphoton approaches. The tools available at present, and newer devices under development, offer the promise of better enabling clinicians to inform and guide PDT treatment planning, thereby optimizing therapeutic outcomes for patients.
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Affiliation(s)
- Kishore R Rollakanti
- Department of Chemical and Biomedical Engineering, Cleveland State University, 2121 Euclid Avenue, Cleveland, OH 44115, USA; and Department of Biomedical Engineering, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA
| | - Stephen C Kanick
- Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755, USA
| | - Scott C Davis
- Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755, USA
| | - Brian W Pogue
- Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755, USA
| | - Edward V Maytin
- Department of Chemical and Biomedical Engineering, Cleveland State University, 2121 Euclid Avenue, Cleveland, OH 44115, USA; Department of Biomedical Engineering, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA; and Department of Dermatology, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA
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21
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Zhang R, Glaser A, Esipova TV, Kanick SC, Davis SC, Vinogradov S, Gladstone D, Pogue BW. Čerenkov radiation emission and excited luminescence (CREL) sensitivity during external beam radiation therapy: Monte Carlo and tissue oxygenation phantom studies. Biomed Opt Express 2012; 3:2381-2394. [PMID: 23082280 PMCID: PMC3470003 DOI: 10.1364/boe.3.002381] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Revised: 08/29/2012] [Accepted: 08/31/2012] [Indexed: 05/29/2023]
Abstract
Radiotherapy generates Čerenkov radiation emission in tissue, and spectral absorption features appearing in the emission spectrum can be used to quantify blood oxygen saturation (S(t)O(2)) from the known absorptions of hemoglobin. Additionally, the Čerenkov light can be used to excite oxygen-sensitive phosphorescence of probe PtG4, whose emission lifetime directly reports on tissue oxygen partial pressure (pO(2)). Thus, it is feasible to probe both hemoglobin S(t)O(2) and pO(2) using external radiation therapy beam to create as an internal light source in tumor tissue. In this study, the sensitivity and spatial origins of these two signals were examined. Emission was detected using a fiber-optic coupled intensifier-gated CCD camera interfaced to a spectrometer. The phosphorescence lifetimes were quantified and compared with S(t)O(2) changes previously measured. Monte Carlo simulations of the linear accelerator beam were used together with tracking of the optical signals, to predict the spatial distribution and zone sensitivity within the phantom. As the fiber-to-beam distance (FBD) varied from 0 to 30 mm, i.e. the distance from the fiber tip to the nearest side of the radiotherapy beam, the effective sampling depth for CR emission changed from 4 to 29 mm for the wavelengths in the range of 600-1000 nm. For the secondary emission (phosphorescence) the effective sampling depth was determined to be in the range of 9 to 19 mm. These results indicate that sampling of S(t)O(2) and pO(2) in tissue should be feasible during radiation therapy, and that the radiation beam and fiber sampling geometry can be set up to acquire signals that originate as deep as a few centimeters in the tissue.
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Affiliation(s)
- Rongxiao Zhang
- Department of Physics & Astronomy, Dartmouth College, Hanover NH 03755, USA
| | - Adam Glaser
- Thayer School of Engineering, Dartmouth College, Hanover NH 03755, USA
| | - Tatiana V. Esipova
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia PA 19104, USA
| | - Stephen C. Kanick
- Thayer School of Engineering, Dartmouth College, Hanover NH 03755, USA
| | - Scott C. Davis
- Thayer School of Engineering, Dartmouth College, Hanover NH 03755, USA
| | - Sergei Vinogradov
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia PA 19104, USA
| | - David Gladstone
- Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon NH 03755, USA
- Department of Medicine, Dartmouth-Hitchcock Medical Center, Lebanon NH 03755, USA
| | - Brian W. Pogue
- Department of Physics & Astronomy, Dartmouth College, Hanover NH 03755, USA
- Thayer School of Engineering, Dartmouth College, Hanover NH 03755, USA
- Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon NH 03755, USA
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22
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Gamm UA, Kanick SC, Sterenborg HJCM, Robinson DJ, Amelink A. Quantification of the reduced scattering coefficient and phase-function-dependent parameter γ of turbid media using multidiameter single fiber reflectance spectroscopy: experimental validation. Opt Lett 2012; 37:1838-40. [PMID: 22660046 DOI: 10.1364/ol.37.001838] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Multidiameter single fiber reflectance (MDSFR) spectroscopy is a method that allows the quantification of μs' and the phase-function-dependent parameter γ of a turbid medium by utilizing multiple fibers with different diameters. We have previously introduced the theory behind MDSFR and its limitations, and here we present an experimental validation of this method based on phantoms containing a fractal distribution of polystyrene spheres both in the absence and presence of the absorber Evans Blue.
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Affiliation(s)
- U A Gamm
- Center for Optical Diagnostics and Therapy, Department of Radiation Oncology, Erasmus Medical Center, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands
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23
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Kanick SC, Robinson DJ, Sterenborg HJCM, Amelink A. Extraction of intrinsic fluorescence from single fiber fluorescence measurements on a turbid medium. Opt Lett 2012; 37:948-50. [PMID: 22378448 DOI: 10.1364/ol.37.000948] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
This study utilizes Monte Carlo simulations of single fiber fluorescence to develop an empirical model that corrects for the influence of scattering and absorption on fluorescence intensity (F(SF)). The model expresses F(SF) in terms of the reduced scattering coefficient (μs') and absorption coefficient (μ(a)), each determined independently at excitation and emission wavelengths (λ(x) and λ(m)), and the fiber diameter (d(f)). This model returns accurate descriptions (mean residual <6%) of F(SF) across a biologically relevant range of μs' and μ(a) values and is insensitive to the form of the scattering phase function.
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Affiliation(s)
- Stephen C Kanick
- Center for Optical Diagnostics and Therapy, Department of Radiation Oncology, Erasmus Medical Center, Rotterdam 3000 CA, The Netherlands.
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24
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Kanick SC, Robinson DJ, Sterenborg HJCM, Amelink A. Semi-empirical model of the effect of scattering on single fiber fluorescence intensity measured on a turbid medium. Biomed Opt Express 2012; 3:137-152. [PMID: 22254174 PMCID: PMC3255331 DOI: 10.1364/boe.3.000137] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Revised: 11/11/2011] [Accepted: 11/11/2011] [Indexed: 05/29/2023]
Abstract
Quantitative determination of fluorophore content from fluorescence measurements in turbid media, such as tissue, is complicated by the influence of scattering properties on the collected signal. This study utilizes a Monte Carlo model to characterize the relationship between the fluorescence intensity collected by a single fiber optic probe (F(SF)) and the scattering properties. Simulations investigate a wide range of biologically relevant scattering properties specified independently at excitation (λ(x)) and emission (λ(m)) wavelengths, including reduced scattering coefficients in the range μ'(s)(λ(x)) ∈ [0.1 - 8]mm(-1) and μ'(s)(λ(m)) ∈ [0.25 - 1] × μ'(s)(λ(x)). Investigated scattering phase functions (P(θ)) include both Henyey-Greenstein and Modified Henyey-Greenstein forms, and a wide range of fiber diameters (d(f) ∈ [0.2 - 1.0] mm) was simulated. A semi-empirical model is developed to estimate the collected F(SF) as the product of an effective sampling volume, and the effective excitation fluence and the effective escape probability within the effective sampling volume. The model accurately estimates F(SF) intensities (r=0.999) over the investigated range of μ'(s)(λ(x)) and μ'(s)(λ(m)), is insensitive to the form of the P(θ), and provides novel insight into a dimensionless relationship linking F(SF) measured by different d(f).
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Affiliation(s)
- S C Kanick
- Center for Optical Diagnostics and Therapy, Department of Radiation Oncology, Erasmus Medical Center, PO Box 2040, 3000 CA Rotterdam, The Netherlands.
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Middelburg TA, Kanick SC, de Haas ERM, Sterenborg HJCM, Amelink A, Neumann MHAM, Robinson DJ. Monitoring blood volume and saturation using superficial fibre optic reflectance spectroscopy during PDT of actinic keratosis. J Biophotonics 2011; 4:721-730. [PMID: 21842485 DOI: 10.1002/jbio.201100053] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Revised: 07/08/2011] [Accepted: 07/25/2011] [Indexed: 05/31/2023]
Abstract
Optically monitoring the vascular physiology during photodynamic therapy (PDT) may help understand patient-specific treatment outcome. However, diffuse optical techniques have failed to observe changes herein, probably by optically sampling too deep. Therefore, we investigated using differential path-length spectroscopy (DPS) to obtain superficial measurements of vascular physiology in actinic keratosis (AK) skin. The AK-specific DPS interrogation depth was chosen up to 400 microns in depth, based on the thickness of AK histology samples. During light fractionated aminolevulinic acid-PDT, reflectance spectra were analyzed to yield quantitative estimates of blood volume and saturation. Blood volume showed significant lesion-specific changes during PDT without a general trend for all lesions and saturation remained high during PDT. This study shows that DPS allows optically monitoring the superficial blood volume and saturation during skin PDT. The patient-specific variability supports the need for dosimetric measurements. In DPS, the lesion-specific optimal interrogation depth can be varied based on lesion thickness.
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Affiliation(s)
- Tom A Middelburg
- Department of Dermatology, Erasmus MC, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands
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Middelburg TA, Kanick SC, de Haas ERM, Sterenborg HJCM, Amelink A, Neumann MHAM, Robinson DJ. Monitoring blood volume and saturation using superficial fibre optic reflectance spectroscopy during PDT of actinic keratosis. J Biophotonics 2011. [PMID: 21842485 DOI: 10.1002/jbio.v4.10] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Optically monitoring the vascular physiology during photodynamic therapy (PDT) may help understand patient-specific treatment outcome. However, diffuse optical techniques have failed to observe changes herein, probably by optically sampling too deep. Therefore, we investigated using differential path-length spectroscopy (DPS) to obtain superficial measurements of vascular physiology in actinic keratosis (AK) skin. The AK-specific DPS interrogation depth was chosen up to 400 microns in depth, based on the thickness of AK histology samples. During light fractionated aminolevulinic acid-PDT, reflectance spectra were analyzed to yield quantitative estimates of blood volume and saturation. Blood volume showed significant lesion-specific changes during PDT without a general trend for all lesions and saturation remained high during PDT. This study shows that DPS allows optically monitoring the superficial blood volume and saturation during skin PDT. The patient-specific variability supports the need for dosimetric measurements. In DPS, the lesion-specific optimal interrogation depth can be varied based on lesion thickness.
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Affiliation(s)
- Tom A Middelburg
- Department of Dermatology, Erasmus MC, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands
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Kanick SC, Gamm UA, Sterenborg HJCM, Robinson DJ, Amelink A. Method to quantitatively estimate wavelength-dependent scattering properties from multidiameter single fiber reflectance spectra measured in a turbid medium. Opt Lett 2011; 36:2997-9. [PMID: 21808384 DOI: 10.1364/ol.36.002997] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
This study utilizes experimentally validated Monte Carlo simulations to identify a mathematical formulation of the reflectance intensity collected by a single fiber probe expressed in terms of the reduced scattering coefficient (μs'), fiber diameter d(fiber), and a property of the first two moments of the scattering phase function (γ). This model is then utilized to accurately obtain wavelength-dependent estimates of μs'(λ) and γ(λ) from multiple single fiber spectral measurements of a turbid medium obtained with different diameters. This method returns accurate descriptions (mean residual <3%) of both μs' and γ across the biologically relevant range.
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Affiliation(s)
- Stephen C Kanick
- Center for Optical Diagnostics and Therapy, Department of Radiation Oncology, Erasmus Medical Center, Rotterdam, The Netherlands.
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Kanick SC, Robinson DJ, Sterenborg HJCM, Amelink A. Method to quantitate absorption coefficients from single fiber reflectance spectra without knowledge of the scattering properties. Opt Lett 2011; 36:2791-3. [PMID: 21808314 DOI: 10.1364/ol.36.002791] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
This study presents a methodology to accurately extract the absorption coefficient from single fiber reflectance spectra measured in turbid media without a priori knowledge of either the reduced scattering coefficient or the phase function. This novel approach accounts for the interrelated effects these properties have on the photon path length, yielding estimates of an absorption coefficient on average within <7.5% of true values over a wide range of biologically relevant optical properties.
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Affiliation(s)
- Stephen C Kanick
- Center for Optical Diagnostics and Therapy, Department of Radiation Oncology, Erasmus Medical Center, Rotterdam 3000 CA, The Netherlands
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Bremmer RH, Kanick SC, Laan N, Amelink A, van Leeuwen TG, Aalders MCG. Non-contact spectroscopic determination of large blood volume fractions in turbid media. Biomed Opt Express 2011; 2:396-407. [PMID: 21339884 PMCID: PMC3038454 DOI: 10.1364/boe.2.000396] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Revised: 01/21/2011] [Accepted: 01/23/2011] [Indexed: 05/08/2023]
Abstract
We report on a non-contact method to quantitatively determine blood volume fractions in turbid media by reflectance spectroscopy in the VIS/NIR spectral wavelength range. This method will be used for spectral analysis of tissue with large absorption coefficients and assist in age determination of bruises and bloodstains. First, a phantom set was constructed to determine the effective photon path length as a function of μ(a) and μ(s)' on phantoms with an albedo range: 0.02-0.99. Based on these measurements, an empirical model of the path length was established for phantoms with an albedo > 0.1. Next, this model was validated on whole blood mimicking phantoms, to determine the blood volume fractions ρ = 0.12-0.84 within the phantoms (r = 0.993; error < 10%). Finally, the model was proved applicable on cotton fabric phantoms.
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Affiliation(s)
- Rolf H. Bremmer
- Biomedical Engineering and Physics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Stephen C. Kanick
- Center for Optical Diagnostics and Therapy, Department of Radiation Oncology,Erasmus Medical Center, Rotterdam, The Netherlands
| | - Nick Laan
- Biomedical Engineering and Physics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Arjen Amelink
- Center for Optical Diagnostics and Therapy, Department of Radiation Oncology,Erasmus Medical Center, Rotterdam, The Netherlands
| | - Ton G. van Leeuwen
- Biomedical Engineering and Physics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
- Biomedical Photonic Imaging, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
| | - Maurice C. G. Aalders
- Biomedical Engineering and Physics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
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Kanick SC, Robinson DJ, Sterenborg HJCM, Amelink A. Monte Carlo analysis of single fiber reflectance spectroscopy: photon path length and sampling depth. Phys Med Biol 2009; 54:6991-7008. [PMID: 19887712 DOI: 10.1088/0031-9155/54/22/016] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Single fiber reflectance spectroscopy is a method to noninvasively quantitate tissue absorption and scattering properties. This study utilizes a Monte Carlo (MC) model to investigate the effect that optical properties have on the propagation of photons that are collected during the single fiber reflectance measurement. MC model estimates of the single fiber photon path length (L(SF)) show excellent agreement with experimental measurements and predictions of a mathematical model over a wide range of optical properties and fiber diameters. Simulation results show that L(SF) is unaffected by changes in anisotropy (g epsilon [0.8, 0.9, 0.95]), but is sensitive to changes in phase function (Henyey-Greenstein versus modified Henyey-Greenstein). A 20% decrease in L(SF) was observed for the modified Henyey-Greenstein compared with the Henyey-Greenstein phase function; an effect that is independent of optical properties and fiber diameter and is approximated with a simple linear offset. The MC model also returns depth-resolved absorption profiles that are used to estimate the mean sampling depth (Z(SF)) of the single fiber reflectance measurement. Simulated data are used to define a novel mathematical expression for Z(SF) that is expressed in terms of optical properties, fiber diameter and L(SF). The model of sampling depth indicates that the single fiber reflectance measurement is dominated by shallow scattering events, even for large fibers; a result that suggests that the utility of single fiber reflectance measurements of tissue in vivo will be in the quantification of the optical properties of superficial tissues.
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Affiliation(s)
- S C Kanick
- Center for Optical Diagnostics and Therapy, Department of Radiation Oncology, Erasmus Medical Center, PO Box 2040, 3000 CA Rotterdam, The Netherlands.
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Kanick SC, Sterenborg HJCM, Amelink A. Empirical model of the photon path length for a single fiber reflectance spectroscopy device. Opt Express 2009; 17:860-71. [PMID: 19158901 DOI: 10.1364/oe.17.000860] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
A reflectance spectroscopic device that utilizes a single fiber for both light delivery and collection has advantages over classical multi-fiber probes. This study presents a novel empirical relationship between the single fiber path length and the combined effect of both the absorption coefficient, mua (range: 0.1-6 mm-1), and the reduced scattering coefficient, micro's (range: 0.3 - 10 mm-1), for different anisotropy values (0.75 and 0.92), and is applicable to probes containing a wide range of fiber diameters (range: 200-2000 microm). The results indicate that the model is capable of accurately predicting the single fiber path length over a wide range (r = 0.995; range: 180-3940 microm) and predictions do not show bias as a function of either microa or micro's .
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Affiliation(s)
- S C Kanick
- Center for Optical Diagnostics and Therapy, Department of Radiation Oncology, Erasmus Medical Center, PO Box 2040, 3000 CA Rotterdam, The Netherlands.
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Kanick SC, Eiseman JL, Parker RS. Pharmacokinetic modeling of motexafin gadolinium disposition in mouse tissues using optical pharmacokinetic system measurements. Photodiagnosis Photodyn Ther 2008; 5:276-84. [DOI: 10.1016/j.pdpdt.2008.11.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2008] [Accepted: 11/24/2008] [Indexed: 01/25/2023]
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Kanick SC, Sterenborg HJCM, Amelink A. Empirical model description of photon path length for differential path length spectroscopy: combined effect of scattering and absorption. J Biomed Opt 2008; 13:064042. [PMID: 19123688 DOI: 10.1117/1.3050424] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Differential path length spectroscopy (DPS) is a method of reflectance spectroscopy that utilizes a specialized fiber geometry to make the photon path length (tau) insensitive to variations in tissue optical properties over a wide range of absorption (mu(a)) and total scattering (mu(s)) coefficients, which are common within the ultraviolet/visible (UV/VIS) wavelength region. This study extends the description of tau to larger mu(a) and smaller mu(s) values, optical properties that are representative of the near-infrared region (NIR), a region where the DPS path length may be dependent on both coefficients. This study presents a novel empirical relationship between tau and the combined effect of both mu(a) (range: 0.1-12 mm(-1)) and mu(s) (range: 1.5-42 mm(-1)), anisotropy of 0.8, and is applicable to DPS probes containing a wide range of fiber diameters (range: 100-1000 microm). The results indicate that the simple empirical formula, including only one fitted parameter, is capable of accurately predicting tau over a wide range (r=0.985; range: 80-940 microm) and predictions are not biased versus mu(a) or mu(s). This novel relationship is applicable to analysis of DPS measurements of tissue in both the UV/VIS and NIR wavelength regions and may provide information about the wavelength-specific tissue volume optically sampled during measurement.
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Affiliation(s)
- Stephen C Kanick
- Erasmus Medical Center, Department of Radiation Oncology, Center for Optical Diagnostics and Therapy, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands.
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Kanick SC, Eiseman JL, Joseph E, Guo J, Parker RS. Noninvasive and nondestructive optical spectroscopic measurement of motexafin gadolinium in mouse tissues: comparison to high-performance liquid chromatography. J Photochem Photobiol B 2007; 88:90-104. [PMID: 17604637 DOI: 10.1016/j.jphotobiol.2007.05.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2006] [Revised: 05/01/2007] [Accepted: 05/09/2007] [Indexed: 12/01/2022]
Abstract
Efficient design of anti-cancer treatments involving radiation- and photo-sensitizing therapeutics requires knowledge of tissue-specific drug concentrations. This study investigates the use of the optical pharmacokinetic system (OPS) to measure concentrations of the anti-cancer agent motexafin gadolinium (MGd) in mouse tissues noninvasively and nondestructively using elastic-scattering spectroscopy. The magnitude of MGd absorbance was quantitated by integration of the MGd peak absorbance area, and MGd concentrations were estimated by comparison with standard curves that were validated by high performance liquid chromatography (HPLC). In tissue-simulating phantoms in vitro, MGd peak absorbance area correlated with MGd concentration. Female C.B-17 SCID mice, bearing subcutaneous MDA-MB-231 human breast cancer xenografts, were dosed with 23 mg/kg MGd i.v. At specific times between 5 min and 24h after dosing, noninvasive OPS measurements were made on skin overlaying the subcutaneous tumor and skin on the opposite flank in vivo, and following exsanguination, nondestructive measurements were made on tumor, skin, and internal tissues in situ. OPS measurements on tissues in vivo detected MGd present in both tissue and blood perfusing the tissue. Both the OPS and the HPLC detected selective localization of MGd in malignant tissues compared with surrounding non-malignant tissues, and neither technique detected MGd in brain tissue. Comparison of MGd concentrations measured by HPLC and OPS is complicated by mismatch between measured tissue volumes, heterogeneous spatial distribution of MGd in tissues, and blood-localized MGd at early time points. Tumor-specific MGd concentrations measured by HPLC correlated with those measured by OPS in vivo and in situ. Best fit lines to the concentration estimates (forced through zero) had slopes of 0.900 and 1.185, respectively; however, the variability was significant (r(2)=0.477 and 0.269). The clinical utility of the OPS to quantitate MGd concentrations remains to be validated.
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Affiliation(s)
- Stephen C Kanick
- Department of Chemical Engineering, University of Pittsburgh, School of Engineering, Pittsburgh, PA 15261, USA
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