Mathematical Modeling of Uniform and Nonuniform Malignian and Normal Tissues Irradiation. Mathematical Analysis of the Tumour Grid Irradiation

2021 ◽  
Vol 91 (3) ◽  
pp. 27-32
Author(s):  
L. Ya. Klepper
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Mathematical Analysis ◽  
Normal Tissue ◽  
Irradiation Dose ◽  
Equivalent Uniform Dose ◽  
Normal Tissues ◽  
Adequate Dose ◽  
Dose Volume ◽  
Significant Interest

Purpose: On base created mathematical model (MM) modified Veybull distribution, intended for NTCP calculation, depending on irradiated volume V and uniform irradiation dose D, to develop the MM, which allows to realize transition from nonuniform dose in tissue to the equivalent, uniform identical dose. To research the hypothesis, under what condition lumpy sharing dose in system tumors+normal tissues will be more efficient, than uniform dose. Material and Methods: Lumpy sharing dose are described as a differential histogram dose-volume (DDVH). The MM for calculation transition lumpy distribution of the absence of the beam complication probability (ACPr) in tissue is designed. It was used for MM conclusion, which allows to calculate transition values of the Adequate Dose (AD) of the uniform irradiation tissues, which use brings about ACPr in tissues. Results: On base of the suggestions and proved affirmation MMs are received, which allow for lumpy distribution of local NTCP values, presented as a DHDV, to calculate transition values ACPr, as well as select from it MM for reduction of the lumpy sharing dose. On base created MM question was explored, in what case tumors and normal tissue through a grid irradiation will be more effective than uniform irradiation. Conclusion: The transition from lumpy sharing doses in tissues to equivalent uniform dose present the significant interest for the RT planning efficiency. Their study is necessary, where the radiation of biosubjects is influenced.

scholarly journals CyberKnife and EDGE in stereotactic body radiotherapy for pancreas cancer: a comparison of plan quality

2020 ◽  
Author(s):  
Zhitao Dai ◽  
Li Ma ◽  
Tingting Cao ◽  
Lian Zhu ◽  
Man Zhao ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Stereotactic Body Radiotherapy ◽  
Normal Tissue ◽  
Pancreas Cancer ◽  
Target Volume ◽  
Conformity Index ◽  
Equivalent Uniform Dose ◽  
Dose Distributions ◽  
Dose Volume ◽  
Comprehensive Comparison

Abstract Purpose: To perform a comprehensive comparison of the different stereotactic body radiotherapy (SBRT) plans between the Varian EDGE and CyberKnife (CK) systems for pancreas cancer.Materials and methods: Fifteen patients with pancreas cancer were selected in this study. The median planning target volume (PTV) was 28.688cm 3 (5.736 to 49.246 cm 3 ). The SBRT plans for the EDGE and CK were generated in the Eclipse and Multiplan systems respectively with the same contouring and dose constrains for PTV and organ at risk (OAR). Dose distributions in PTV were evaluated in terms of coverage, conformity index (CI), new conformity index (nCI), homogeneity index (HI), and gradient index (GI). OARs, including spinal cord, bowel, stomach, duodenum and kidneys were statistically evaluated by different dose-volume metrics and equivalent uniform dose (EUD) . The volume covered by the different isodose lines (ISDL) ranging from 10% to 100% for normal tissue were also analyzed.Results: All SBRT plans for EDGE and CK met the clinical requirement for PTV and OARs. . For the PTV, the dosimetric metrics in EDGE plans were lower than that in CK, except that D 99 and GI were slightly higher. The EDGE plans with lower CI , nCI and HI were superior to offer the better conformity and homogeneity for PTV. For the normal tissue, the CK plans were better at OARs sparing. The radiobiological indices EUD of spinal cord, duodenum, stomach, and kidneys were lower for CK plans, except that liver were higher. The volumes of normal tissue covered by medium ISDLs (with range of 20%~70%) were lower for CK plans while that covered by high and low ISDLs were lower for EDGE plans.Conclusions: This study indicated that both EDGE and CK generated equivalent plan quality, and both systems can be considered as beneficial techniques for SBRT of pancreas cancer. EDGE plans offered the better conformity and homogeneity of dose distributions for PTV, while the CK plans could minimize the exposure of OARs.

scholarly journals Creation of a Forecasting Information System in Epidemiology based on Mathematical Modeling

Webology ◽  
2021 ◽  
Vol 18 (2) ◽  
pp. 388-412
Author(s):  
Aliya Takuadina ◽  
Aliya Kintonova ◽  
Nurlan Tabriz ◽  
Anna Knaus ◽  
Natalya Demidchik
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Information System ◽  
Data Processing ◽  
Mathematical Analysis ◽  
Main Part ◽  
Mathematical Methods ◽  
Factors Affecting ◽  
Statistical Program ◽  
Spread Of Infection

The article is devoted to the problem of using mathematical methods for forecasting the tuberculosis epidemic in Kazakhstan using the example of the Karaganda region. The introduction of the article reflects the problem of forecasting tuberculosis in Kazakhstan. The main part of the article reflects the results of the analysis of mathematical methods for forecasting and data processing technology, describes the mathematical analysis of epidemiological indicators made with the SPSS statistical program, describes the factors affecting the incidence among contact persons, and calculates the correlation coefficient. The article shows the importance of mathematical modeling and the importance of developing a specific mathematical model that describes the spread of infection among the population.

Strahlenwirkung am Normalgewebe

2010 ◽  
Vol 49 (S 01) ◽  
pp. S53-S58 ◽  
Author(s):  
W. Dörr
Keyword(s):  
Radiation Exposure ◽  
Normal Tissue ◽  
Radiation Effects ◽  
A Priori ◽  
Cell Loss ◽  
Turnover Time ◽  
Complete Healing ◽  
Internal Radiotherapy ◽  
Normal Tissues ◽  
Chronic Radiation

SummaryThe curative effectivity of external or internal radiotherapy necessitates exposure of normal tissues with significant radiation doses, and hence must be associated with an accepted rate of side effects. These complications can not a priori be considered as an indication of a too aggressive therapy. Based on the time of first diagnosis, early (acute) and late (chronic) radiation sequelae in normal tissues can be distinguished. Early reactions per definition occur within 90 days after onset of the radiation exposure. They are based on impairment of cell production in turnover tissues, which in face of ongoing cell loss results in hypoplasia and eventually a complete loss of functional cells. The latent time is largely independent of dose and is defined by tissue biology (turnover time). Usually, complete healing of early reactions is observed. Late radiation effects can occur after symptom-free latent times of months to many years, with an inverse dependence of latency on dose. Late normal tissue changes are progressive and usually irreversible. They are based on a complex interaction of damage to various cell populations (organ parenchyma, connective tissue, capillaries), with a contribution from macrophages. Late effects are sensitive for a reduction in dose rate (recovery effects).A number of biologically based strategies for protection of normal tissues or for amelioration of radiation effects was and still is tested in experimental systems, yet, only a small fraction of these approaches has so far been introduced into clinical studies. One advantage of most of the methods is that they may be effective even if the treatment starts way after the end of radiation exposure. For a clinical exploitation, hence, the availability of early indicators for the progression of subclinical damage in the individual patient would be desirable. Moreover, there is need to further investigate the molecular pathogenesis of normal tissue effects in more detail, in order to optimise biology based preventive strategies, as well as to identify the precise mechanisms of already tested approaches (e. g. stem cells).

Application of the method of mathematical modeling for forecasting channel deformations at the underwater crossing of the main pipeline

2020 ◽  
Vol 10 (6) ◽  
pp. 599-609
Author(s):  
Valery А. Gruzdev ◽  
◽  
Georgy V. Mosolov ◽  
Ekaterina A. Sabayda ◽  
◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Roughness Coefficient ◽  
Computational Domain ◽  
Channel Deformations ◽  
Geological Surveys ◽  
Kuban River ◽  
The Stability ◽  
Protective Structures

In order to determine the possibility of using the method of mathematical modeling for making long-term forecasts of channel deformations of trunk line underwater crossing (TLUC) through water obstacles, a methodology for performing and analyzing the results of mathematical modeling of channel deformations in the TLUC zone across the Kuban River is considered. Within the framework of the work, the following tasks were solved: 1) the format and composition of the initial data necessary for mathematical modeling were determined; 2) the procedure for assigning the boundaries of the computational domain of the model was considered, the computational domain was broken down into the computational grid, the zoning of the computational domain was performed by the value of the roughness coefficient; 3) the analysis of the results of modeling the water flow was carried out without taking the bottom deformations into account, as well as modeling the bottom deformations, the specifics of the verification and calibration calculations were determined to build a reliable mathematical model; 4) considered the possibility of using the method of mathematical modeling to check the stability of the bottom in the area of TLUC in the presence of man-made dumping or protective structure. It has been established that modeling the flow hydraulics and structure of currents, making short-term forecasts of local high-altitude reshaping of the bottom, determining the tendencies of erosion and accumulation of sediments upstream and downstream of protective structures are applicable for predicting channel deformations in the zone of the TLUC. In all these cases, it is mandatory to have materials from engineering-hydro-meteorological and engineering-geological surveys in an amount sufficient to compile a reliable mathematical model.

Resveratrol as an Adjuvant for Normal Tissues Protection and Tumor Sensitization

2020 ◽  
Vol 20 (2) ◽  
pp. 130-145 ◽  
Author(s):  
Keywan Mortezaee ◽  
Masoud Najafi ◽  
Bagher Farhood ◽  
Amirhossein Ahmadi ◽  
Dheyauldeen Shabeeb ◽  
...  
Keyword(s):  
Targeted Therapy ◽  
Cancer Treatment ◽  
Cancer Cells ◽  
Clinical Studies ◽  
Normal Tissue ◽  
Medical Science ◽  
Treatment Modalities ◽  
Radiation Toxicity ◽  
Normal Tissues ◽  
Normal Tissue Toxicity

Cancer is one of the most complicated diseases in present-day medical science. Yearly, several studies suggest various strategies for preventing carcinogenesis. Furthermore, experiments for the treatment of cancer with low side effects are ongoing. Chemotherapy, targeted therapy, radiotherapy and immunotherapy are the most common non-invasive strategies for cancer treatment. One of the most challenging issues encountered with these modalities is low effectiveness, as well as normal tissue toxicity for chemo-radiation therapy. The use of some agents as adjuvants has been suggested to improve tumor responses and also alleviate normal tissue toxicity. Resveratrol, a natural flavonoid, has attracted a lot of attention for the management of both tumor and normal tissue responses to various modalities of cancer therapy. As an antioxidant and anti-inflammatory agent, in vitro and in vivo studies show that it is able to mitigate chemo-radiation toxicity in normal tissues. However, clinical studies to confirm the usage of resveratrol as a chemo-radioprotector are lacking. In addition, it can sensitize various types of cancer cells to both chemotherapy drugs and radiation. In recent years, some clinical studies suggested that resveratrol may have an effect on inducing cancer cell killing. Yet, clinical translation of resveratrol has not yielded desirable results for the combination of resveratrol with radiotherapy, targeted therapy or immunotherapy. In this paper, we review the potential role of resveratrol for preserving normal tissues and sensitization of cancer cells in combination with different cancer treatment modalities.

On the displacements of the contours of the optic-electronic space images. Mathematical modeling of displacement

2017 ◽  
Vol 992 (4) ◽  
pp. 32-38 ◽  
Author(s):  
E.G. Voronin
Keyword(s):  
Mathematical Modeling ◽  
Remote Sensing ◽  
Mathematical Model ◽  
Point Of View ◽  
Design Features ◽  
Space Images ◽  
Electronic Imaging ◽  
Measuring Accuracy ◽  
Physical Laws

The article opens a cycle of three consecutive publications dedicated to the phenomenon of the displacement of the same points in overlapping scans obtained adjacent CCD matrices with opto-electronic imagery. This phenomenon was noticed by other authors, but the proposed explanation for the origin of displacements and the resulting estimates are insufficient, and developed their solutions seem controversial from the point of view of recovery of the measuring accuracy of opticalelectronic space images, determined by the physical laws of their formation. In the first article the mathematical modeling of the expected displacements based on the design features of a scanning opto-electronic imaging equipment. It is shown that actual bias cannot be forecast, because they include additional terms, which may be gross, systematic and random values. The proposed algorithm for computing the most probable values of the additional displacement and ways to address some of the systematic components of these displacements in a mathematical model of optical-electronic remote sensing.

scholarly journals Engineering Mathematical Analysis Method for Productivity Rate in Linear Arrangement Serial Structure Automated Flow Assembly Line

2015 ◽  
Vol 2015 ◽  
pp. 1-10
Author(s):  
Tan Chan Sin ◽  
Ryspek Usubamatov ◽  
M. A. Fairuz ◽  
Mohd Fidzwan B. Md. Amin Hamzas ◽  
Low Kin Wai
Keyword(s):  
Mathematical Model ◽  
Failure Rate ◽  
Mathematical Analysis ◽  
Assembly Line ◽  
Flow Line ◽  
Analysis Method ◽  
Machining Time ◽  
Linear Arrangement ◽  
Final Assembly ◽  
Productivity Rate

Productivity rate (Q) or production rate is one of the important indicator criteria for industrial engineer to improve the system and finish good output in production or assembly line. Mathematical and statistical analysis method is required to be applied for productivity rate in industry visual overviews of the failure factors and further improvement within the production line especially for automated flow line since it is complicated. Mathematical model of productivity rate in linear arrangement serial structure automated flow line with different failure rate and bottleneck machining time parameters becomes the basic model for this productivity analysis. This paper presents the engineering mathematical analysis method which is applied in an automotive company which possesses automated flow assembly line in final assembly line to produce motorcycle in Malaysia. DCAS engineering and mathematical analysis method that consists of four stages known as data collection, calculation and comparison, analysis, and sustainable improvement is used to analyze productivity in automated flow assembly line based on particular mathematical model. Variety of failure rate that causes loss of productivity and bottleneck machining time is shown specifically in mathematic figure and presents the sustainable solution for productivity improvement for this final assembly automated flow line.

Clinical comparative study of dose–volume and equivalent uniform dose based predictions in post radiotherapy acute complications

2009 ◽  
Vol 48 (7) ◽  
pp. 1044-1053 ◽  
Author(s):  
Thierry P. Boulé ◽  
M. Isabel Gallardo Fuentes ◽  
Joan V. Roselló ◽  
Rafael Arrans Lara ◽  
José. L. Torrecilla ◽  
...  
Keyword(s):  
Comparative Study ◽  
Equivalent Uniform Dose ◽  
Dose Volume ◽  
Acute Complications
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