Meditsinskaya Fizika最新文献

{"title":"Hypothesis about Celluar Structure of Tumor Tissues and Probability of Her Curing Depending on Plan of RT","authors":"N. Antipina, L. I. Klepper","doi":"10.52775/1810-200x-2023-97-1-33-42","DOIUrl":"https://doi.org/10.52775/1810-200x-2023-97-1-33-42","url":null,"abstract":"Purpose: In 1988 Withers H.R., Taylor J.M., Maciejewski B., proposed a hypothesis about the cellular structure of normal body tissues, according to which their radioresistance is determined by the presence of functional cellular units (FСU) in them. But, unfortunately, in their work there was no substantiation of this hypothesis. \u0000In our work, we substantiate the hypothesis that tumor tissue contains structured tissue-like formations (TLF) from malignant cells that determine its radioresistance. The success of radiation therapy is determined both by the destruction of TLF and the death of their fragments and free clonogenic cells formed as a result of the breakdown of TLF. \u0000Material and methods: To substantiate the hypothesis, mathematical models were created that made it possible to describe the results of radiation exposure to squamous cell carcinoma of the larynx (CL) and breast cancer (BC) after surgical removal of the BC tumor and total irradiation of breast to destroy cells that could migrate from tumor. For segregation of the parameters values that characterize the radiosensitivity of the tumor and for plotting a dose-response curve, a special method was developed for Reconstruction the Radiobiological Tumor Parameters (RRTP), based on the Poisson mathematical model and other mathematical models used in radiation therapy planning. \u0000Results: Dependencies of radiobiological parameters on the dose were plotted using the RRTP method: \u00001. Dependence of the number of tumor units N on the dose, which include TLF, TLF fragments and independent tumor cells formed as a result of TLF decay after irradiation. \u00002. Dependence of the radiobiological parameter t (D,d) Gy–1 on the total dose and dose per fraction. \u00003. Dependence of the radiobiological parameter g (D,d) Gy on total dose and dose per fraction. \u0000In this paper, it is shown that for CL the number of tumor units N and the parameter t (D,d) are increasing functions of the dose D. This confirms the hypothesis that CL consists of TLF, which, after irradiation, decompose into TLF fragments and independent tumor cells. For breast cancer, it was found, as expected, that the number of tumor units N is a decreasing function of the dose D, i.e., that there are no TLF formations in breast cancer. \u0000Conclusion: The hypothesis that the CL tumor contains TPO formations from malignant cells, which increase its radioresistance was confirmed. At a dose close to the therapeutic dose, the number of tumor units becomes close to the number of all tumor cells.","PeriodicalId":222791,"journal":{"name":"Meditsinskaya Fizika","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129248425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of the Quality and Comparison of Dosimetric Parameters of Plans for Craniospinal Irradiation Using VMAT Method at Varian TrueBeam and Varian Halcyon Accelerators","authors":"A. E. Gumbatova, A. Ovsyannikov, I. Lebedenko, I. I. Luzina","doi":"10.52775/1810-200x-2022-96-4-30-36","DOIUrl":"https://doi.org/10.52775/1810-200x-2022-96-4-30-36","url":null,"abstract":"Purpose: To carry out a comparative analysis of the dosimetric characteristics of plans for craniospinal irradiation (CSI) performed by the VMAT technique on Varian TrueBeam and Halcyon electron accelerators. \u0000Material and methods: Comparison of dose distributions was carried out for a group of 5 patients with tumors of the central nervous system. Contouring and planning were in Eclipse version 15.6. The following dose characteristics were calculated and evaluated: homogeneity index (HI), conformity index (CI), target coverage (CO) and constraints (lenses, esophagus, lungs, heart, liver, bowel bag and kidneys). Patient-Specific QA was performed to verify the consistency of the dose distribution calculated in the planning system and obtained at the accelerators. \u0000Results: For all CSI plans the target coverage metric was D98>95 % and constraints for critical organs were obtained. Homogeneity index was HI<=0.12 for two accelerators. The mean value of the CI conformity index was 1.09 for the TrueBeam accelerator, and CI=1.12 for the Halcyon. Gamma analysis showed results within tolerance both plans at TrueBeam and Halcyon. Conclusions have been made about the advantages and disadvantages of CSI on TrueBeam and Halcyon electron accelerators. \u0000Conclusion: It is possible to treat patients with the CSI method on the Halcyon accelerator using the VMAT method with the same quality as on the TrueBeam accelerator.","PeriodicalId":222791,"journal":{"name":"Meditsinskaya Fizika","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116188037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Criteria for the Applicability of Computer Vision for Preventive Studies on the Example of Chest X-Ray and Fluorography","authors":"K. Arzamasov, S. Semenov, D. Kokina, T. Bobrovskaya, N. Pavlov, Y. Kirpichev, A. Andreychenko, A. Vladzymyrskyy","doi":"10.52775/1810-200x-2022-96-4-56-63","DOIUrl":"https://doi.org/10.52775/1810-200x-2022-96-4-56-63","url":null,"abstract":"Purpose: In the conditions of a constant increase in the number of computer vision algorithms developed based on artificial intelligence (AI) for medical diagnostics, it becomes necessary to determine criteria for deciding whether their practical application for mass preventive studies of the population is appropriate. \u0000Materials and methods: The study with the participation of several radiologists was conducted on a “Web platform for evaluating radiological studies” on a marked data set containing digital radiographs and fluorograms in an anterior direct projection. On the same data set, using the “Versioning Testing Platform”, responses were obtained from two commercial AI-based computer vision algorithms developed for the analysis of digital radiographs. Evaluation of the results obtained from doctors and algorithms (binary, in terms of “with pathology” and “without pathology”) was carried out using ROC analysis. For the threshold value calculated by the Yuden method, the following metrics were determined: sensitivity, specificity and accuracy. \u0000Results: diagnostic accuracy metrics were calculated for the average assessment of radiologists and AI-based computer vision algorithms when searching for pathological changes on chest X-rays in anterior direct projection according to ROC analysis. The average values of diagnostic accuracy indicators of radiologists exceeded the indicators of AI services. \u0000Conclusions: when deciding on the implementation of AI-based computer vision algorithms for preventive research, One should be guided by the metrics of diagnostic accuracy of a particular algorithm and use the average result of doctors in solving this diagnostic problem as the target values of metrics.","PeriodicalId":222791,"journal":{"name":"Meditsinskaya Fizika","volume":"89 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133340263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improvement of Proton Irradiation Effectiveness of Human Lung Carcinoma Cells A 549 in the Presence of Gold Nanoparticles","authors":"A. V. Rzyanina, G. Mitsyn, S. V. Shvidkij, A. Molokanov, K. Shipulin, A. Agapov, V. Gaevsky, I. Khassenova","doi":"10.52775/1810-200x-2022-96-4-21-29","DOIUrl":"https://doi.org/10.52775/1810-200x-2022-96-4-21-29","url":null,"abstract":"Purpose: To study was to study the effect of GNP nanoparticles on tumor cells of human lung carcinoma A 549 when irradiated with protons. \u0000Materials and methods: \u0000Cell culture: Human lung carcinoma cells A 549. \u0000Gold nanoparticles Au/PEG 6000/W 200/30 nm: A colloidal solution of gold nanoparticles purchased from the firm M 9 Nanomaterials & Technologies was used in the work. \u0000Proton irradiation: The irradiation of cells was carried out on a therapeutic proton beam in the Medical and Technical Complex of the Laboratory of Nuclear Problems Joint Institute for Nuclear Research. \u0000Determination of radiosensitivity of cells: By determining the clonogenic survival of cells. \u0000Determination of the genotoxic activity of nanoparticles under the action of proton irradiation: investigated using a micronucleus test with blocking cytokinesis. The genotoxicity of gold nanoparticles was estimated by the number of micronuclei per 1000 binuclear cells. Micronucleus were counted only in binuclear cells. At least 1000 binuclear cells were calculated for each dose, experiments were carried out in three repeats. \u0000Results: The frequency of micronucleus formation indicates an increase in the genotoxic effect of nanoparticles when irradiated with protons at a dose of 2 Gy. Proton irradiation caused an increase in the frequency of micronucleus formation depending on the concentration of nanoparticles. When irradiated with protons at a dose of 2 Gy in the presence and absence of nanoparticles, the difference in the frequency of micronucleus formation for the concentration of nanoparticles was 2.5 mg/ml – 1.1; for 5 mg/ml and 10 mg/ml – 1.2; for 15 mg/ml – 1.3 and for 30 mg/ml –1.5. Cell survival curves reflect a decrease in their survival rate when metal nanoparticles with high Z are added, which reflects the occurrence of radiosensitization effects. The gain for 10 % and 50 % survival rates is 1.4 and 2.5, respectively. \u0000Conclusions: Under the influence of proton irradiation, the genotoxic activity of gold nanoparticles in human lung carcinoma cells A 549 increases, depending on their concentration. The survival rate of human lung carcinoma A 549 cells irradiated with protons in the presence of gold nanoparticles decreases.","PeriodicalId":222791,"journal":{"name":"Meditsinskaya Fizika","volume":"76 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116698999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of Hemoglobin Conformation Changes in Patients with Pulmonary Hypertension under the Action of Alternating Magnetic Field","authors":"S. Mamaeva, A. Pavlov, O. Slatinskaya, G. Maksimov","doi":"10.52775/1810-200x-2022-96-4-72-80","DOIUrl":"https://doi.org/10.52775/1810-200x-2022-96-4-72-80","url":null,"abstract":"The influence of magnetic field on human health is still not fully understood. The effects of short-term and long-term effects of both, strong and weak electric and magnetic fields are being actively studied. \u0000One of the main areas of research is the study of the effect of magnetic fields on the blood and on individual blood components, in particular the hemoglobin molecule. The purpose of this research work is to study of short term (1, 15 and 30 minutes) influence of 300 mT alternating magnetic field (AMF), which is equivalent to that observed from conventional sources of statistical magnetic field, on isolated hemoglobin, as well as on hemoglobin in erythrocytes of blood samples of donors with pulmonary hypertension before and after treatment with Raman spectroscopy. The effect of AMF on both the conformation of heme (iron-containing site) and its protein part (globin) has been established, hence the effect on the ability of hemoglobin to bind ligands, in particular oxygen. Change in the level of oxygenated and deoxygenated hemoglobin and an increase in the probability of finding hemoglobin in T-form were revealed. A change in the polarity of the environment of amino acid residues was also revealed. There was a decrease in the polarity of the environment of amino acid residues, as well as the ordering and density of amino acids. In experiments with erythrocytes, a significant increase in cell membrane fluidity was observed.","PeriodicalId":222791,"journal":{"name":"Meditsinskaya Fizika","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126595031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of CT Protocols for Newborn Patients by Ingenuity 128, Philips. A Phantom Study","authors":"P. S. Druzhinina, L. Chipiga, I. Shatskiy, A. Vodovatov, A. Pozdnyakov, V. G. Puzyrev, A. I. Tashchilkin, D. A. Malikov, N. Potrakhov, Y. Potrakhov","doi":"10.52775/1810-200x-2022-96-4-43-55","DOIUrl":"https://doi.org/10.52775/1810-200x-2022-96-4-43-55","url":null,"abstract":"Purpose: To evaluate the impact of CT scan protocol parameters on patient dose and image quality for optimization of protocols for newborn patients. \u0000Materials and methods: Three anatomical areas (chest, abdomen and combined chest + abdomen area) of a newborn PH-50 Newborn Whole-Body Phantom (Kyoto Kagaku Co, LTD, Japan) were scanned on Ingenuity 128 CT scanner (Philips) using different scan parameters. The values of weighted CT dose index (CTDIvol) and dose length product (DLP) were used as dose characteristics and the noise of CT image was chosen to estimate the image quality. The noise was determined in the soft tissues in the areas of shoulder girdle and diaphragm in images with the reconstruction kernel B, as well as in lung tissue of lung apices for images with the reconstruction kernel YC for chest and chest + abdomen; and in soft tissues (for reconstruction kernel B) in the area of the diaphragm for abdomen. \u0000Results: The analysis of the impact of tube voltage and dose right index (DRI) on dose characteristics and image quality made it possible to determine the optimal parameters of CT protocols for selected CT department: chest – 80 kV at DRI -– 19, abdomen – 100 kV at DRI – 22, chest + abdomen – 120 kV at DRI – 22. These protocol parameters provide an effective dose of newborn patients – 1.4, 1.7 and 2,8 mSv for chest, abdomen and chest + abdomen scans, respectively. \u0000Conclusion: The impact of different scan parameters (tube voltage and DRI) of chest, abdomen and chest + abdomen protocols on patient dose and image noise was evaluated. The study allowed setting optimized protocol parameters to improve the image quality.","PeriodicalId":222791,"journal":{"name":"Meditsinskaya Fizika","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129365581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Scanning Water Phantom Quality Assurance","authors":"Zh. S. Lebedeva, D. D. Granin, P. Medvedev, O. V. Pashkov","doi":"10.52775/1810-200x-2022-96-4-81-88","DOIUrl":"https://doi.org/10.52775/1810-200x-2022-96-4-81-88","url":null,"abstract":"CONTENT \u0000Introduction \u0000Current recommendations \u0000Positioning the detector and phantom \u0000Detectors and electronics \u0000Scanned dosimetry data acquisition \u0000Output \u0000Comparison of commercially available phantoms \u0000Conclusion","PeriodicalId":222791,"journal":{"name":"Meditsinskaya Fizika","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114198294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Examination of the Surface of Erythrocytes of Patients with Cervical Cancer by Immunofluorescence Analysis","authors":"S. Mamaeva, V. Alekseev, I. Kononova, N. Nikolaeva, T. A. Krylova, A. Pavlov, A. Gabysheva, G. Maksimov","doi":"10.52775/1810-200x-2022-96-4-64-71","DOIUrl":"https://doi.org/10.52775/1810-200x-2022-96-4-64-71","url":null,"abstract":"The number of patients diagnosed with cervical cancer continues to increase all over the world. Despite the intensive development of diagnostic and therapy methods, the phenomenon of relapses in the absence of a clear explanation for their occurrence, and of metastasis are observed, which complicates treatment and affects the survival of patients. In this regard, there is a need to develop new research methods for a more detailed study of the occurrence and development of the disease at the molecular and cellular levels, as well as the effectiveness of treatment and the causes of relapses. \u0000In this paper, nanoparticles are studied on the surface of red blood cells, which were revealed by the authors using scanning electron microscopy previously, and results of the study of blood samples of patients with cervical cancer using a new sample preparation method and immunofluorescence analysis for their identification are presented on the basis of the assumption that these nanoparticles are viral particles. \u0000With the combination of immunofluorescence and electron microscopy methods, we were able to confirm our hypothesis of the viral nature of nanoparticles attached to the surface of red blood cells of patients diagnosed with cervical cancer. With this approach, it was found that the particles of human papillomavirus 16 and 18 are located on the cytoplasmic membrane of red blood cells. The results of this study indicate that viruses circulate in the patient's blood, and are attached to the surface of red blood cells. This apparently affects the development of cervical cancer, its relapse, and metastasis.","PeriodicalId":222791,"journal":{"name":"Meditsinskaya Fizika","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127131695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Verification of Uniformity of Dosimetric Characteristics of Couch Tops in Proton Radiation Therapy","authors":"S. A. Vladimirkin, V. Kiselev, A. Demidova, Y. Udalov, S. E. Gritsenko, A. A. Oraskina","doi":"10.52775/1810-200x-2022-96-4-12-20","DOIUrl":"https://doi.org/10.52775/1810-200x-2022-96-4-12-20","url":null,"abstract":"In proton therapy the couches used for patient positioning and alignment can affect the uncertainty in the dose distribution from the applied proton beam. In order to limit the additional uncertainty of the proton range, it is necessary to know the determined water equivalent thickness (WET) of the couch top and carefully reflect it in the calculations of the dosimetry planning system. The method presented in this article is based on the difference in the measured depth of the proton beam detected by the multilayer ionization chamber with the beam passing through the couch top and without passing through it. \u0000A range shifter (proton beam modifier) installed in the nozzle with the known WET for evaluating couch tops before commissioning was used in this research work. A nozzle is a proton beam delivery system consisting of quadrupole magnets, ionization chambers and an X-ray tube. CT scans were also acquired to evaluate the internal homogeneity of the test couch tops. \u0000Several kVue couch inserts Proton one (Qfix Systems, Avondale, PA) were evaluated in this study. The results show that the inserts are largely interchangeable for this type of design and the use of the range shifter during treatment, using gantry angles with the proton beam passing through the couch top, does not affect its WET, adding a deflection of approximately 0.1 mm. It was also determined that the reproducibility of the WET determination method has a deviation less than ±0.03 mm. In conclusion, the described above method of couch top testing before commissioning in proton therapy can also be applied to other patient immobilization systems.","PeriodicalId":222791,"journal":{"name":"Meditsinskaya Fizika","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126277137","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Increasing to Accuracy Reductions Heterogeneous Dose Distribution to All-Out Volume of the Irradiation at Models Modified Weibull Distribution","authors":"L. I. Klepper","doi":"10.52775/1810-200x-2022-96-4-5-11","DOIUrl":"https://doi.org/10.52775/1810-200x-2022-96-4-5-11","url":null,"abstract":"Purpose: To development of the methods of the estimation quality, systematized clinical information, which is described in the manner of probability of the arising the NTCP (complications in tissues) depending on volume of the irradiation and sharing the dose their uniform and heterogeneous irradiation. \u0000Material and methods: Used designed mathematical models for calculation of NTCP and mathematical models, which allow to calculate reduction values of the identical doses of the uniform irradiation tissues equivalent on probability of the arising the beam complication to heterogeneous sharing the doses. \u0000Results: Method of increasing to precision of the estimation to consensus systematized clinical information, founded on its presentation in the manner of differential histogram dose-volume, and on reductions heterogeneous doses distribution in identical dose all-out and uniform irradiation tissue. \u0000Conclusion: It is shown that designed method of the estimation of the heterogeneous sharing the dose by way of his adduction to equivalent, on probability of the arising the beam complications in tissues, all-out irradiations tissues, allows to raise accuracy of the calculation of the identical dose of the source lumpy distribution tolerants doses. She allows to raise precision of the estimation to consensus systematized clinical values of tolerant doses, received of specialist.","PeriodicalId":222791,"journal":{"name":"Meditsinskaya Fizika","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124952128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}