Elastic light-scattering spectra acquired with single-fiber optical probes with diameters of 100, 200, 400, 600, 800, 1000, 1200, and 1500 μm were used to differentiate cancerous from noncancerous prostate tissues. The spectra were acquired ex vivo on 24 excised prostate tissue samples collected from four patients. For each probe, the spectra and histopathology results were compared in order to investigate the correlation between the core diameters of the single-fiber optical probe and successful differentiation between cancerous and noncancerous prostate tissues. The spectra acquired using probes with a fiber core diameter of 400 μm or smaller successfully differentiated cancerous from noncancerous prostate tissues. Next, the spectra were acquired from monosized polystyrene microspheres with a diameter of 5.00±0.01 μm to investigate the correlation between the core diameters of the probes and the Mie oscillations on the spectra. Monte Carlo simulations of the light distribution of the tissue phantoms were run to interrogate whether the light detected by the probes with different fiber core diameters was in the ballistic or diffusive regime. If the single-fiber optical probes detect light in the ballistic regime, the spectra can be used to differentiate between cancerous and noncancerous tissues.
Elastic light single-scattering spectroscopy (ELSSS) system has been developed and tested in diagnosis of cancerous tissues of different organs. ELSSS system consists of a miniature visible light spectrometer, a single fiber optical probe, a halogen tungsten light source and a laptop. Measurements were performed on excised brain, skin, cervix and prostate tumor specimens and surrounding normal tissues. Single fiber optical probe with a core diameter of 100 μm was used to deliver white light to and from tissue. Single optical fiber probe mostly detects singly scattered light from tissue rather than diffused light. Therefore, measured spectra are sensitive to size of scatters in tissue such as cells, nuclei, mitochondria and other organelles of cells. Usually, nuclei of tumor cells are larger than nuclei of normal cells. Therefore, spectrum of singly scattered light of tumor tissue is different than normal tissue. The spectral slopes were shown to be positive for normal brain, skin and prostate and cervix tissues and negative for the tumors of the same tissues. Signs of the spectral slopes were used as a discrimination parameter to differentiate tumor from normal tissues for the three organ tissues. Sensitivity and specificity of the system in differentiation between tumors from normal tissues were 93% and %100 for brain, 87% and 85% for skin, 93.7% and 46.1% for cervix and 98% and 100% for prostate.
Elastic light single-scattering spectroscopy (ELSSS) system with a single optical fiber probe was employed to
differentiate cancerous prostate tissue from non-cancerous prostate tissue ex-vivo just after radical prostatectomy. First,
ELSSS spectra were acquired from cancerous prostate tissue to define its spectral features. Then, spectra were acquired
from surgical margins of excised prostate tissue to detect positive surgical margins based on the spectral features of the
spectra taken from cancerous prostate tissues. Of the total 128 tissue samples were evaluated from 18 patients by ELSSS
system. Comparing of histopathology results and ELSSS measurements revealed that sign of the spectral slopes of
cancerous prostate tissue is negative and non-cancerous tissue is positive in the wavelength range from 450 to 750 nm.
Sign of the spectral slopes were used as a discrimination parameter between cancerous and non-cancerous prostate
tissues. Based on the correlation between histopathology results and sign of the spectral slopes, ELSSS system
differentiates cancerous prostate tissue from non-cancerous with a sensitivity of 0.97 and a specificity of 0.87.
Joint cartilage thickness has been estimated using spatially resolved steady-state reflectance spectroscopy noninvasively
and in-real time. The system consists of a miniature UV-VIS spectrometer, a halogen tungsten light source, and an
optical fiber probe with six 400 um diameter fibers. The first fiber was used to deliver the light to the cartilage and the
other five were used to detect back-reflected diffused light. Distances from the detector fibers to the source fiber were
0.8 mm, 1.6 mm, 2.4 mm, 3.2 mm and 4 mm. Spectra of back-reflected diffused light were taken on 40 bovine patella
cartilages. The samples were grouped into four; the first group was the control group with undamaged cartilages, in the
2nd, 3rd and 4th groups cartilage thickness was reduced approximately 25%, 50% and 100%, respectively. A correlation
between cartilage thicknesses and hemoglobin absorption of light in the wavelength range of 500 nm- 600 nm for source-detector
pairs was found. The proposed system with an optical fiber probe less than 4 mm in diameter has the potential
for cartilage thickness assessment through an arthroscopy channel in real-time without damaging the cartilage.
We have investigated the potential application of elastic light single-scattering spectroscopy (ELSSS) as an adjunctive tool
for screening of cervical precancerous lesions non-invasively and in real time. Ex-vivo measurements were performed on
95 cervix biopsy tissue of 60 patients. Normal cervix tissue from 10 patients after hysterectomy was used as a control
group. Correlation between ELSSS spectra and histopathology results were investigated. It was found that the spectral
slope was positive for all the spectra taken on normal cervix tissue samples from the control group. We assumed that if
there is only one spectrum with a negative spectral slope among the all spectra taken on a biopsy specimen, the biopsy
specimen is pathologically abnormal. This shows that pap smear and ELSSS results are in good agreement. Most biopsy
tissue samples had both positive and negative spectral slopes. Therefore, we calculated the percentage of negative spectral
slopes and hypothesized that this was correlated to dysplastic percentage of the epithelial tissue of the biopsy material.
The ROC curve was calculated using the dysplastic percentage and high squamous intraepithelial lesion (HSIL) and low
squamous intraepitherlial lesions (LSIL) biopsy specimens were differentiated from non HSIL and LSIL with a sensitivity
and specificity of 70.4% and 66.7% respectively, with p < 0.05.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.