scholarly journals Optical biopsy: fundamentals and applications in neurosurgery

2021 ◽  
Vol 2058 (1) ◽  
pp. 012024
Author(s):  
T A Savelieva ◽  
I D Romanishkin ◽  
Yu S Maklygina ◽  
P V Grachev ◽  
N A Kalyagina ◽  
...  
Keyword(s):  
Optical Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Intraoperative Imaging ◽  
Spectroscopic Method ◽  
Tumor Resection ◽  
Nerve Fibers ◽  
Intraoperative Navigation ◽  
Optical Biopsy ◽  
Intramedullary Tumors

Abstract Currently, there is a significant increase in the incidence of cancer of the central nervous system. Determination of the boundaries of intracerebral and intramedullary tumors is especially difficult. The urgency of the problem of determining the boundaries of astrocytic tumors is due to the peculiarities of their growth along myelinated nerve fibers and vessels, leading to the infiltration of healthy white matter by tumor cells, which affects the high frequency of postoperative relapses. The complexity of surgery for intramedullary tumors of the spinal cord is that the tumor does not always have a clear border and the risk of injury is high due to the smaller size of the operated area compared to the brain. Reliable information regarding the volume of the resected tumor should be obtained by intraoperative imaging. The solution to this problem is implemented mainly in three directions: the use of intraoperative computed tomography, magnetic resonance imaging and ultrasound scanning, and various combinations of these methods. Unfortunately, all these methods of intraoperative diagnostics do not allow real-time examination of tissues in an operating wound and/or do not provide a simultaneous analysis of both structural and metabolic changes. The limitations of intraoperative navigation methods in neurosurgery have led to the relevance of the development of an accurate spectroscopic method for in vivo determination of the content of specific metabolic markers and structural changes accompanying the development of the tumor process in the nervous tissue. Various approaches to intraoperative navigation based on optical spectroscopy are called optical biopsy. In this article, we present the methods and tools developed in recent years for spectroscopic guidance in neurooncology. First of all, this, of course, concerns the analysis of spectral dependences recorded before, during and after tumor removal. We have used such modalities of optical spectroscopy as fluorescence, diffuse reflectance spectroscopy and spontaneous Raman scattering. An equally important issue on the way to increasing the efficiency of tumor resection is the development of new instrumentation; therefore, we have developed a number of new devices, which are a combination of well-known neurosurgical instruments and laser and fiber-optic technologies. Last but not least is the issue of rapid classification of the studied tissues based on the recorded signals, which was solved by us using machine learning methods.

Cross-polarization Optical Coherence Tomography Probes for Intraoperative Application in Neurosurgery

2020 ◽  
Author(s):  
Konstantin Yashin ◽  
Pavel Shilyagin ◽  
Elena Kiseleva ◽  
Grigory Gelikonov ◽  
Vladimir Romashov ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Brain Tissue ◽  
Beam Quality ◽  
Intraoperative Imaging ◽  
Nerve Fibers ◽  
Optical Biopsy ◽  
Tissue Imaging ◽  
Optical Coherence ◽  
Cross Polarization ◽  
Different Types

Optical coherence tomography (OCT) is one of the most promising, innovative and rapidly emerging intraoperative imaging modalities for neurosurgical guidance in brain tissue imaging, "optical biopsy", brain cerebral vascular detection, nerve fibers and white matter tracts detection. In this article, we provide a short survey of cross-polarization OCT and different types of OCT probes that can be used in routine neurosurgical practice. Through different types of probes there are multiple applications where OCT can play a highly complementary role in offering the real-time microscopic assessment and imaging of normal and pathological brain tissues. The biopsy-needle based probe for CP OCT was shown to be an effective instrument for brain tissue mapping and express estimation of tissue status as well as for detecting large blood vessels to prevent causing bleeding during biopsy sampling. The folded CP OCT probe for intraoperative use for brain tissue examination was shown as a potentially efficient sensor head for CP OCT. The probe demonstrated high lateral resolution in diffractive limited probing beam quality. The length of dismountable probe tip allows using the probe under operating microscope. Due to the designed family of specialized probes CP OCT fills in the niche of devices for express brain tissue examination in situ.

Stellenwert der Navigation

2017 ◽  
Vol 01 (04) ◽  
pp. 317-334
Author(s):  
Jan-Sven Jarvers ◽  
Ulrich Spiegl ◽  
Stefan Glasmacher ◽  
Christoph Heyde ◽  
Christoph Josten
Keyword(s):  
Patient Safety ◽  
Radiation Exposure ◽  
Pedicle Screw ◽  
Spinal Surgery ◽  
Intraoperative Imaging ◽  
Intraoperative Navigation ◽  
Advantages And Disadvantages ◽  
Tumor Diseases ◽  
Intraoperative Control ◽  
Improved Technology

Abstract Importance of Navigation Navigation and intraoperative imaging have undergone an enormous development in recent years. By using intraoperative navigation, the precision of pedicle screw implantation can be increased in the sense of patient safety. Especially in the case of complex defects or tumor diseases, navigation is a decisive aid. As a result of the constantly improved technology, the requirements for reduced radiation exposure and intraoperative control can also be met. The high costs of the devices can be amortized, for example by a reduced number of revisions. This overview presents the principles of navigation in spinal surgery and the advantages and disadvantages of the different navigation procedures.

UV spectroscopic method for determination of phenytoin in bulk and injection forms

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Quality Control ◽  
Spectrophotometric Method ◽  
Spectroscopic Method ◽  
Ich Guidelines ◽  
Precision And Accuracy ◽  
Routine Quality Control

Recent study was conducted to develop a simple UV spectrophotometric method to determine Phenytoin in bulk and injection form according to official requirement and validate as per ICH guidelines. λmax of Phenytoin was found 202 nm. Linearity existed perceived in the concentration assortment 2-8 μg/ml (r2 = 0.999) for the method. The method was validated pertaining to linearity, precision and accuracy studies, LOD and LOQ consistent with ICH guidelines. The existent method was establish to be simple, linear, precise, accurate as well as sensitive and can be applied for routine quality control enquiry for the analysis of Phenytoin in bulk and injection form.

Development and Validation of Derivative Spectroscopic Method for Simultaneous Estimation of Cefadroxil and Probenecid

2014 ◽  
Vol 7 (1) ◽  
pp. 2350-2355
Author(s):  
Pratik S Mehta ◽  
Pratik R. Patel ◽  
Rajesh R Parmar ◽  
M M K Modasiya ◽  
Dushyant A Shah
Keyword(s):  
Spectroscopic Method ◽  
Spectral Interference ◽  
Synthetic Mixture ◽  
Simultaneous Estimation ◽  
Zero Crossing ◽  
First Order ◽  
Derivative Spectroscopy ◽  
Development And Validation ◽  
Crossing Point

A novel, simple, accurate, sensitive, precise and economical derivative spectroscopic method was developed and validated for the determination of cefadroxil and probenecid in synthetic mixture. First order derivative spectroscopy method was adopted to eliminate spectral interference. The method obeys Beer’s Law in concentration ranges of 4-36 μg/ml for cefadroxil and of 5-25 μg/ml of probenecid. The zero crossing point for cefadroxil and probenecid was 260 nm and 237.8 nm respectively in 0.1N HCl. The method was validated in terms of accuracy, precision, linearity, limits of detection, limits of quantitation. This method has been successively applied to synthetic mixture and no interference from the synthetic mixture’s excipients was found.   

Accurate determination of the onset wavelength (λonset) in optical spectroscopy

2021 ◽  
Vol 265 ◽  
pp. 107544
Author(s):  
Austin M. Wallace ◽  
Christine Curiac ◽  
Jared H. Delcamp ◽  
Ryan C. Fortenberry
Keyword(s):  
Optical Spectroscopy ◽  
Accurate Determination

scholarly journals An SPRi Biosensor for Determination of the Ovarian Cancer Marker HE4 in Human Plasma

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3567
Author(s):  
Beata Szymanska ◽  
Zenon Lukaszewski ◽  
Beata Zelazowska-Rutkowska ◽  
Kinga Hermanowicz-Szamatowicz ◽  
Ewa Gorodkiewicz
Keyword(s):  
Ovarian Cancer ◽  
Cancer Patients ◽  
Tumor Resection ◽  
Analytical Signal ◽  
Cancer Marker ◽  
Human Epididymis Protein 4 ◽  
Pearson Coefficient ◽  
Rabbit Polyclonal Antibody ◽  
Good Agreement

Human epididymis protein 4 (HE4) is an ovarian cancer marker. Various cut-off values of the marker in blood are recommended, depending on the method used for its determination. An alternative biosensor for HE4 determination in blood plasma has been developed. It consists of rabbit polyclonal antibody against HE4, covalently attached to a gold chip via cysteamine linker. The biosensor is used with the non-fluidic array SPRi technique. The linear range of the analytical signal response was found to be 2–120 pM, and the biosensor can be used for the determination of the HE4 marker in the plasma of both healthy subjects and ovarian cancer patients after suitable dilution with a PBS buffer. Precision (6–10%) and recovery (101.8–103.5%) were found to be acceptable, and the LOD was equal to 2 pM. The biosensor was validated by the parallel determination of a series of plasma samples from ovarian cancer patients using the Elecsys HE4 test and the developed biosensor, with a good agreement of the results (a Pearson coefficient of 0.989). An example of the diagnostic application of the developed biosensor is given—the influence of ovarian tumor resection on the level of HE4 in blood serum.

scholarly journals Sodium Fluorescein for Spinal Intradural Tumors

2021 ◽  
Vol 10 ◽  
Author(s):  
Semih Kivanc Olguner ◽  
Ali Arslan ◽  
Vedat Açık ◽  
İsmail İstemen ◽  
Mehmet Can ◽  
...  
Keyword(s):  
Staining Pattern ◽  
Tumor Resection ◽  
Sodium Fluorescein ◽  
Histopathological Diagnosis ◽  
Tumor Surgery ◽  
Intramedullary Tumors ◽  
Fluorescein Staining ◽  
Yellow Filter ◽  
Intradural Tumor ◽  
Intradural Extramedullary

Technological innovations in spinal intradural tumor surgery simplify treatment. Surgical treatment of cranial benign and malignant pathologies under microscope with sodium (Na)-fluorescein guidance has often been reported, but few studies have focused on spinal intradural tumors. We aimed to investigate the usefulness of Na-fluorescein under yellow filter in intradural spinal tumor surgery by retrospectively reviewing cases involving intramedullary and extramedullary tumors operated under the guidance of Na-fluorescein. Forty-nine adult patients with a diagnosis of spinal intradural tumor operated under a yellow filter (560 nm) microscope using Na-fluorescein dye were included in the study. Demographic data, such as age and sex, neurological status, extent of tumor resection, histopathological diagnosis, Na-fluorescein staining pattern, and its usefulness during surgery were noted and statistically analyzed. Of all recruited patients, 26 women (53.1%) and 23 men (46.9%), were included for analysis. The age range of the patients was 18–64 years, with a mean age of 41.6 ± 13.9. An intradural intramedullary mass was found in 30.6% (n = 15) of the patients, and an intradural extramedullary mass in 69.4% (n: 34). While Na-fluorescein staining was homogeneous in all intradural extramedullary tumors, 73.3% (n: 11) of intradural intramedullary tumors were homogeneous, and 13.3% (n: 2) moderately heterogeneous. In the whole study group, the Na-fluorescein staining pattern was helpful in surgical resection in 47 cases (95.9%). While 34/34 (100%) found it helpful for extramedullary tumors, 13/15 (86.7%) did in intramedullary tumors, and for 2/15 (13.3%) it was not. In conclusion, Na-fluorescein helps in distinguishing tumor from healthy tissue in intradural extramedullary and intramedullary tumor surgery under a yellow filter microscope in most cases, thus providing convenient assistance to surgeons.

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