Abstract:
:Photodynamic therapy (PDT) is an alternative to radical surgical resection for T1a or nonresectable carcinomas of the gastroesophageal junction. Besides the concentration of the photosensitizer, the light distribution in tissue is responsible for tumor destruction. For this reason, knowledge about the behavior of light in healthy and dysplastic tissue is of great interest for careful irradiation scheduling. The aim of this study is to determine the optical parameters (OP) of healthy and carcinomatous tissue of the gastroesophageal junction in vitro to provide reproducible parameters for optimal dosimetry when applying PDT. A total of 36 tissue samples [adenocarcinoma tissue (n=21), squamous cell tissue (n=15)] are obtained from patients with carcinomas of the gastroesophageal junction. The optical parameters are measured in 10-nm steps using new integrating sphere spectrometers in the PDT-relevant wavelength range of 300 to 1140 nm and evaluated by inverse Monte-Carlo simulation. Additional examinations are done in healthy tissue from the surgical safety margin. In the wavelength range of frequently applied photosensitizers at 330, 630, and 650 nm, the absorption coefficient in tumor tissue (adenocarcinoma 1.22, 0.16, and 0.15 mm(-1); squamous cell carcinoma 1.48, 0.13, and 0.11 mm(-1)) is significantly lower than in healthy tissue (stomach 3.34, 0.26, and 0.20 mm(-1); esophagus 2.47, 0.21, and 0.18 mm(-1)). The scattering coefficient of all tissues decreases continuously with increasing wavelength (adenocarcinoma 22.8, 12.99, and 12.52 mm(-1); squamous cell carcinoma 19.44, 9.35, and 8.98 mm(-1); stomach 20.55, 13.96, and 13.94 mm(-1); esophagus 20.34, 12.56, and 12.22 mm(-1). All tissues show an anisotropy factor between 0.80 and 0.94 over the entire spectrum. The maximum optical penetration depth for all tissues is achieved in the range of 800 to 1100 nm. At the wavelength range of 330, 630, and 650 nm, the optical penetration depth is significantly higher in carcinoma tissue (adenocarcinoma 0.27, 1.54, and 1.66 mm; squamous cell carcinoma 0.23, 1.71, and 1.84 mm) than in healthy tissue (stomach 0.16, 1.10, and 1.26 mm; esophagus 0.17, 1.47, and 1.65 mm; p<0.05). Above 1000 nm, a higher absorption coefficient of tumor tissue results in a lower optical penetration depth than in healthy tissue (p<0.05). The higher absorption and scattering of the tumor tissue in the wavelength range of available photosensitizer is associated with a low optical penetration depth. This necessitates higher energy doses and long application times or repeated applications to effectively treat large tumor volumes. Photosensitizers optimized for larger wavelength range need to be developed to increase the efficacy of PDT.
journal_name
J Biomed Optjournal_title
Journal of biomedical opticsauthors
Holmer C,Lehmann KS,Wanken J,Reissfelder C,Roggan A,Mueller G,Buhr HJ,Ritz JPdoi
10.1117/1.2564793subject
Has Abstractpub_date
2007-01-01 00:00:00pages
014025issue
1eissn
1083-3668issn
1560-2281journal_volume
12pub_type
杂志文章abstract::The effect of silica/gold nanoshells and titanium dioxide nanoparticles on the optical properties of skin is studied. By implementing in vivo measurements and Monte Carlo simulations, we analyze the efficiency of using these nanoparticles as contrasting agents for optical coherence tomography (OCT) imaging of skin. In...
journal_title:Journal of biomedical optics
pub_type: 杂志文章
doi:10.1117/1.3122373
更新日期:2009-03-01 00:00:00
abstract:SIGNIFICANCE:The potential of fluorescence lifetime imaging microscopy (FLIM) is recently being recognized, especially in biological studies. However, FLIM does not directly measure the lifetimes, rather it records the fluorescence decay traces. The lifetimes and/or abundances have to be estimated from these traces dur...
journal_title:Journal of biomedical optics
pub_type: 杂志文章
doi:10.1117/1.JBO.26.2.022909
更新日期:2021-01-01 00:00:00
abstract::Polarization interferometry (PI) techniques, which are able to improve surface plasmon resonance (SPR) sensing performance and reduce restrictions on allowable parameters of SPR-supporting metal films, have been experimentally realized only in SPR sensors using monochromatic light as a source. Wavelength-interrogation...
journal_title:Journal of biomedical optics
pub_type: 杂志文章
doi:10.1117/1.JBO.17.3.036002
更新日期:2012-03-01 00:00:00
abstract::We experimentally compare the performance and image contrast of spontaneous Raman and coherent Stokes Raman scattering microscopy. We demonstrate the differences between these techniques on a series of geometry-controlled samples that range in complexity from a point (array of tips) to one-dimensional (line grating) a...
journal_title:Journal of biomedical optics
pub_type: 杂志文章
doi:10.1117/1.3533310
更新日期:2011-02-01 00:00:00
abstract::Angle-resolved optical scattering properties of ovarian tissue, on different optical coherence tomography (OCT) imaging planes, were quantitatively measured by fitting the compounded OCT A-lines into a single scattering model. Higher cross correlation value of angle-resolved scattering coefficients between different O...
journal_title:Journal of biomedical optics
pub_type: 信件
doi:10.1117/1.JBO.17.9.090503
更新日期:2012-09-01 00:00:00
abstract::We present a simple wide-field imaging technique, called HiLo microscopy, that is capable of producing optically sectioned images in real time, comparable in quality to confocal laser scanning microscopy. The technique is based on the fusion of two raw images, one acquired with speckle illumination and another with st...
journal_title:Journal of biomedical optics
pub_type: 杂志文章
doi:10.1117/1.3528656
更新日期:2011-01-01 00:00:00
abstract::Dental erosion starts with a chemical attack on dental tissue causing tooth demineralization, altering the tooth structure and making it more sensitive to mechanical erosion. Medical diagnosis of dental erosion is commonly achieved through a visual inspection by the dentist during dental checkups and is therefore high...
journal_title:Journal of biomedical optics
pub_type: 杂志文章
doi:10.1117/1.JBO.21.7.071103
更新日期:2016-07-01 00:00:00
abstract::Two pronounced absorption peaks in blue and red ranges of the chlorin-based photosensitizer (PS) absorption spectrum provide additional benefits in photodynamic therapy (PDT) performance. Differing optical properties of biological tissues in these ranges allow for both dual-wavelength diagnostics and PDT performance. ...
journal_title:Journal of biomedical optics
pub_type: 杂志文章
doi:10.1117/1.JBO.25.6.063804
更新日期:2019-12-01 00:00:00
abstract::The fibrillar collagen network in tumor and normal tissues is different due to remodeling of the extracellular matrix during the malignant process. Collagen type I fibers have the crystalline and noncentrosymmetric properties required for generating the second-harmonic signal. The content and structure of collagen wer...
journal_title:Journal of biomedical optics
pub_type: 杂志文章
doi:10.1117/1.2983664
更新日期:2008-09-01 00:00:00
abstract::In the present study, we evaluated the applicability of ex vivo photoacoustic imaging (PAI) on small animal organs. We used photoacoustic tomography (PAT) to visualize infarcted areas within murine hearts and compared these data to other imaging techniques [magnetic resonance imaging (MRI), micro-computed tomography] ...
journal_title:Journal of biomedical optics
pub_type: 杂志文章
doi:10.1117/1.3556720
更新日期:2011-03-01 00:00:00
abstract::We demonstrate a single-camera imaging system that can simultaneously acquire brightfield, darkfield, and phase contrast images in real time. Our method uses computational illumination via a programmable light-emitting diode (LED) array at the source plane, providing flexible patterning of illumination angles. Brightf...
journal_title:Journal of biomedical optics
pub_type: 杂志文章
doi:10.1117/1.JBO.19.10.106002
更新日期:2014-01-01 00:00:00
abstract::The essential feature of the confocal laser scanning microscope (cLSM) is the generation of optical sections by the removal of out-of-focus light. About ten years ago, structured illumination microscopy (SIM) was introduced as an alternative method for obtaining optical sections from biological specimens. Here we comp...
journal_title:Journal of biomedical optics
pub_type: 杂志文章
doi:10.1117/1.3083439
更新日期:2009-01-01 00:00:00
abstract::We report on wide-field imaging of pulsatile motion induced by blood flow using heterodyne holographic interferometry on the thumb of a healthy volunteer, in real time. Optical Doppler images were measured with green laser light by a frequency-shifted Mach-Zehnder interferometer in off-axis configuration. The recorded...
journal_title:Journal of biomedical optics
pub_type: 杂志文章
doi:10.1117/1.JBO.20.6.066006
更新日期:2015-06-01 00:00:00
abstract::Obstruction in the upper airway can often cause reductions in breathing or gas exchange efficiency and lead to rest disorders such as sleep apnea. Imaging diagnosis of the obstruction region has been accomplished using computed tomography (CT) and magnetic resonance imaging (MRI). However CT requires the use of ionizi...
journal_title:Journal of biomedical optics
pub_type: 信件
doi:10.1117/1.jbo.17.11.110507
更新日期:2012-11-01 00:00:00
abstract::The nEUROPt protocol is one of two new protocols developed within the European project nEUROPt to characterize the performances of time-domain systems for optical imaging of the brain. It was applied in joint measurement campaigns to compare the various instruments and to assess the impact of technical improvements. T...
journal_title:Journal of biomedical optics
pub_type: 杂志文章
doi:10.1117/1.JBO.19.8.086012
更新日期:2014-08-01 00:00:00
abstract::Abdominal surgeries carry considerable risk of gastrointestinal and intra-abdominal hemorrhage, which could possibly cause patient death. Photoacoustic imaging is one solution to overcome this challenge by providing visualization of major blood vessels during surgery. We investigate the feasibility of in vivo blood ve...
journal_title:Journal of biomedical optics
pub_type: 杂志文章
doi:10.1117/1.JBO.24.12.121905
更新日期:2019-08-01 00:00:00
abstract::Fast estimation of optical properties from reflectance measurements at two spatial frequencies could pave way for real-time, wide-field and quantitative mapping of vital signs of tissues. We present a machine learning-based approach for estimating optical properties in the spatial frequency domain, where a random fore...
journal_title:Journal of biomedical optics
pub_type: 杂志文章
doi:10.1117/1.JBO.24.7.071606
更新日期:2018-12-01 00:00:00
abstract::For clinical optoacoustic imaging, linear probes are preferably used because they allow versatile imaging of the human body with real-time display and free-hand probe guidance. The two-dimensional (2-D) optoacoustic image obtained with this type of probe is generally interpreted as a 2-D cross-section of the tissue ju...
journal_title:Journal of biomedical optics
pub_type: 杂志文章
doi:10.1117/1.JBO.18.2.026011
更新日期:2013-02-01 00:00:00
abstract::It is widely known that not all of the treated cells survive after introduction of exogenous molecules via any physical method. Therefore, it is important to develop methods that would allow simultaneous evaluation of both molecular delivery efficiency and cell viability. This study presents Förster resonance energy t...
journal_title:Journal of biomedical optics
pub_type: 杂志文章
doi:10.1117/1.JBO.22.9.097001
更新日期:2017-09-01 00:00:00
abstract::Spatially resolved spectroscopy (SRS) allows the estimation of absolute tissue oxygen saturation, the ratio of oxygenated to total hemoglobin concentration, which may facilitate the comparison of results among patients. Eighty-two premature infants were included over two years. The cerebral tissue oxygenation index (c...
journal_title:Journal of biomedical optics
pub_type: 杂志文章
doi:10.1117/1.3013454
更新日期:2008-11-01 00:00:00
abstract::This paper presents comprehensive and depth-resolved retinal microvasculature images within human retina achieved by a newly developed ultrahigh sensitive optical microangiography (UHS-OMAG) system. Due to its high flow sensitivity, UHS-OMAG is much more sensitive to tissue motion due to the involuntary movement of th...
journal_title:Journal of biomedical optics
pub_type: 杂志文章
doi:10.1117/1.3642638
更新日期:2011-10-01 00:00:00
abstract::The earliest steps of breast cancer begin with aberrations in mammary ductal structure. Techniques that enable an investigator to image in situ and then analyze the same tissue using biochemical tools facilitates identification of genetic networks and signaling pathways active in the imaged structure. Cellular confoca...
journal_title:Journal of biomedical optics
pub_type: 杂志文章
doi:10.1117/1.2065827
更新日期:2005-09-01 00:00:00
abstract::Spectrally resolved two-photon excited autofluorescence imaging is used to distinguish different cell types and functional areas during dynamic processes in the living gut. Excitation and emission spectra of mucosal tissue and tissue components are correlated to spectra of endogenous chromophores. We show that selecti...
journal_title:Journal of biomedical optics
pub_type: 杂志文章
doi:10.1117/1.3655587
更新日期:2011-11-01 00:00:00
abstract::We have been developing a Mach-Zehnder type of optical frequency domain reflectometry optical coherence tomography (OFDR-OCT) that uses discretely swept superstructure-grating distributed Bragg- reflector (SSG-DBR) lasers developed for telecommunication fields and has a 12-mm-depth range. We report images obtained wit...
journal_title:Journal of biomedical optics
pub_type: 杂志文章
doi:10.1117/1.2839042
更新日期:2008-01-01 00:00:00
abstract::Most reconstruction algorithms used in photoacoustic tomography do not account for the effects of acoustic attenuation on the recorded signals. For experimental measurements made in biological tissue, the frequency dependent acoustic attenuation causes high frequency components of the propagating photoacoustic waves t...
journal_title:Journal of biomedical optics
pub_type: 杂志文章
doi:10.1117/1.JBO.18.3.036008
更新日期:2013-03-01 00:00:00
abstract::We present methods for visualizing the dynamic response of biological samples to laser-induced heating. Our approach utilizes optical frequency-domain imaging to detect, spatially localize, and monitor unique dynamic signatures that arise within zones of active tissue denaturation. Since this information is precisely ...
journal_title:Journal of biomedical optics
pub_type: 杂志文章
doi:10.1117/1.2714027
更新日期:2007-03-01 00:00:00
abstract::Renal ischemia that occurs intraoperatively during procedures requiring clamping of the renal artery (such as renal procurement for transplantation and partial nephrectomy for renal cancer) is known to have a significant impact on the viability of that kidney. To better understand the dynamics of intraoperative renal ...
journal_title:Journal of biomedical optics
pub_type: 杂志文章
doi:10.1117/1.JBO.18.3.035001
更新日期:2013-03-01 00:00:00
abstract::We examine the morphological and chemical changes in the pulp chamber dentin after using endodontic agents by scanning electron microscopy (SEM), Fourier transform Raman spectroscopy (FT-Raman), and micro energy-dispersive x-ray fluorescence spectrometry (μEDXRF). Thirty teeth were sectioned exposing the pulp chamber ...
journal_title:Journal of biomedical optics
pub_type: 杂志文章
doi:10.1117/1.JBO.17.7.075008
更新日期:2012-07-01 00:00:00
abstract::Optical measurements of metabolism are ideally acquired in vivo; however, intravital measurements are often impractical. Accurate ex vivo assessments would greatly broaden the applicability of optical measurements of metabolism. We investigate the use of live tissue culture experiments to serve as a surrogate for in v...
journal_title:Journal of biomedical optics
pub_type: 杂志文章
doi:10.1117/1.JBO.17.11.116015
更新日期:2012-11-01 00:00:00
abstract::The objective of the study is the quantitative analysis of the dose-time dependences of changes occurring in collagen of bladder and rectum after gamma-irradiation using optical methods [nonlinear microscopy in a second harmonic generation (SHG) detection regime and cross-polarization optical coherence tomography (CP ...
journal_title:Journal of biomedical optics
pub_type: 杂志文章
doi:10.1117/1.JBO.23.9.091417
更新日期:2018-08-01 00:00:00