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2.
Brachytherapy ; 22(1): 9-11, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36725201

RESUMO

Brachytherapy is a sophisticated and proven treatment technique of different GI localizations. Here the development of GI- brachytherapy of last 20 years, current position and the perspectives for next years are discussed. In summary: The GI-brachytherapy of different localizations is very effective, in experienced hands a safe technique and should be part of armamentarium of every radiation oncologist.


Assuntos
Braquiterapia , Humanos , Braquiterapia/métodos
5.
Brachytherapy ; 22(1): 6-8, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36725200

RESUMO

In the last 20 years, gynecologic brachytherapy has made tremendous advancements, most prominently evidenced by the evolution of cervical cancer brachytherapy. In its 20 year history, Brachytherapy has become known as a journal of science, education, and advocacy for our specialty and for our patients. In this review, we celebrate the 25 most impactful manuscripts in gynecologic brachytherapy in the journal's history.


Assuntos
Braquiterapia , Neoplasias do Colo do Útero , Humanos , Feminino , Braquiterapia/métodos , Neoplasias do Colo do Útero/radioterapia
6.
Hinyokika Kiyo ; 69(1): 1-6, 2023 Jan.
Artigo em Japonês | MEDLINE | ID: mdl-36727454

RESUMO

In our hospital, 553 patients with clinically localized prostate cancer underwent low-dose-rate (LDR) brachytherapy between March 2007 and December 2019. The patients were stratified based on the following prognosis according to the D'Amico risk classification criteria: low-risk and intermediate-risk groups (PSA <10, ≦T2a, GS : 3+4 (≦30%)) were treated with LDR brachytherapy without supplemental extra beam radiotherapy (EBRT), while some patients in the high- and intermediate-risk groups were treated with LDR and supplemental EBRT. The 5- and 10-year overall survival rates were 94.8 and 85.5%, disease-specific survival rates were 99.8 and 97.7%, and biochemical recurrence-free survival rates were 95.7 and 90.7%. By risk stratification, the 5- and 10-year biochemical recurrence-free survival rates were 98.0 and 98.0% (low risk), 96.1 and 89.6% (intermediate risk), and 90.6 and 77.3% (high risk). The LDR outcome was generally good, but, 32 recurrence cases were observed. In the recurrent group, 9 patients did not undergo the recommended therapeutic strategy and 26 patients did not undergo preoperative magnetic resonance imaging.


Assuntos
Braquiterapia , Neoplasias da Próstata , Masculino , Humanos , Braquiterapia/efeitos adversos , Braquiterapia/métodos , Antígeno Prostático Específico , Neoplasias da Próstata/radioterapia , Prognóstico , Dosagem Radioterapêutica
7.
Radiología (Madr., Ed. impr.) ; 65(1): 12-21, ene.-feb. 2023. tab
Artigo em Espanhol | IBECS | ID: ibc-215019

RESUMO

Objetivo Contribuir con la presentación de los resultados de nuestro estudio a ampliar la evidencia científica sobre el empleo de la radioembolización en el manejo de pacientes con hepatocarcinoma. Material y método Se trata de una revisión retrospectiva realizada en nuestro centro que incluye a 53 pacientes con hepatocarcinoma tratados con radioembolización. Los pacientes fueron clasificados según el algoritmo del BCLC (Barcelona Clinic Liver Cancer) y de forma pormenorizada por su estado funcional siguiendo la clasificación de Child-Pugh. Se realizó un estudio de supervivencia siguiendo la metodología de Kaplan-Meier. Se empleó el método de regresión de Cox para la determinación de parámetros clínicos significativos, incluyendo dosis administradas en los parámetros estudiados. Resultados La serie evaluada comprende a pacientes con una media de edad de 60 años (rango 28-86). Se llevaron a cabo un total de 61 procedimientos. La actividad media administrada fue de 2,8 GBq (0,7-6,4 GBq), administrando una dosis media en tumor de 229,9 Gy (74-425,9 Gy). El tiempo libre de progresión fue de 6,7 meses desde el momento del tratamiento y la supervivencia global fue de 12,8 meses. La clasificación de los pacientes según BCLC (p=0,848) y Child-Pugh (p=0,252) no resultó significativa respecto al tiempo libre de enfermedad. Los parámetros clínicos que resultaron con diferencias significativas en cuanto a supervivencia global fueron los niveles de bilirrubina (p<0.001) y las cifras de transaminasas (GOT) pretratamiento (p=0.022), la subclasificación Child-Pugh (p=0.003) y la dosis recibida por el tumor (p=0,001). Tan solo uno de los pacientes tratados presentó un efecto adverso grave, con fallo hepático posterapia y resultado de muerte... (AU)


Objective To contribute our results to increase the scientific evidence about the use of radioembolization in the management of patients with hepatocellular carcinoma. Material and methods This retrospective review included 53 patients with hepatocellular carcinoma treated with radioembolization at our center. Patients were classified according to the BCLC algorithm in detail according to their Child-Pugh functional status. We analyzed survival using the Kaplan-Meier method. We used Cox regression analysis to determine clinically significant parameters, including the doses administered in the parameters studied. Results Patients ranged in age from 28 to 86 years (mean, 60 years). A total of 61 procedures were done. The mean activity administered was 2.8 GBq (0.7-6.4 GBq), with a mean dose of 229.9Gy (74-425.9Gy) administered in the tumor. Progression-free survival was 6.7 months and overall survival was 12.8 months. Differences in disease-free survival according to BCLC and Child-Pugh classification were not significant (p=0.848 and p=0.252, respectively). The clinical parameters that were significantly different with respect to overall survival were bilirubin levels (p<0.001), pretreatment transaminase levels (AST) (p=0.022), Child-Pugh subclassification (p=0.003), and dose administered in the tumor (p=0.001). Only one patient had a severe adverse reaction, developing posttreatment liver failure resulting in death. Conclusions Radioembolization is safe and efficacious in the treatment of patients with hepatocellular carcinoma. Liver function and the doses received by the tumor are key parameters for the efficacy of treatment. The increase in the scientific evidence supports the inclusion of this technique in treatment guidelines. (AU)


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Carcinoma Hepatocelular/radioterapia , Neoplasias Hepáticas/radioterapia , Braquiterapia/métodos , Radioisótopos de Ítrio/uso terapêutico , Estimativa de Kaplan-Meier , Resultado do Tratamento , Estudos Retrospectivos
9.
Technol Cancer Res Treat ; 22: 15330338221139164, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36601655

RESUMO

Introduction: Segmentation of clinical target volume (CTV) from CT images is critical for cervical cancer brachytherapy, but this task is time-consuming, laborious, and not reproducible. In this work, we aim to propose an end-to-end model to segment CTV for cervical cancer brachytherapy accurately. Methods: In this paper, an improved M-Net model (Mnet_IM) is proposed to segment CTV of cervical cancer from CT images. An input and an output branch are both proposed to attach to the bottom layer to deal with CTV locating challenges due to its lower contrast than surrounding organs and tissues. A progressive fusion approach is then proposed to recover the prediction results layer by layer to enhance the smoothness of segmentation results. A loss function is defined on each of the multiscale outputs to form a deep supervision mechanism. Numbers of feature map channels that are directly connected to inputs are finally homogenized for each image resolution to reduce feature redundancy and computational burden. Result: Experimental results of the proposed model and some representative models on 5438 image slices from 53 cervical cancer patients demonstrate advantages of the proposed model in terms of segmentation accuracy, such as average surface distance, 95% Hausdorff distance, surface overlap, surface dice, and volumetric dice. Conclusion: A better agreement between the predicted CTV from the proposed model Mnet_IM and manually labeled ground truth is obtained compared to some representative state-of-the-art models.


Assuntos
Braquiterapia , Aprendizado Profundo , Neoplasias do Colo do Útero , Feminino , Humanos , Neoplasias do Colo do Útero/diagnóstico por imagem , Neoplasias do Colo do Útero/radioterapia , Tomografia Computadorizada por Raios X/métodos , Processamento de Imagem Assistida por Computador/métodos
10.
PLoS One ; 18(1): e0280038, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36662688

RESUMO

Distributed software applications are one of the most important applications currently used. Rising demand has led to a rapid increase in the number and complexity of distributed software applications. Such applications are also more vulnerable to different types of attacks due to their distributed nature. Detecting and addressing attacks is an open issue concerning distributed software applications. This paper proposes a new mechanism that uses blockchain technology to devise a security testing mechanism to detect attacks on distributed software applications. The proposed mechanism can detect several categories of attacks, such as denial-of-service attacks, malware and others. The process starts by creating a static blockchain (Blockchain Level 1) that stores the software application sequence obtained using software testing techniques. This sequence information exposes weaknesses in the application code. When the application is executed, a dynamic blockchain (Blockchain Level 2) helps create a static blockchain for recording the responses expected from the application. Every response should be validated using the proposed consensus mechanism associated with static and dynamic blockchains. Valid responses indicate the absence of attacks, while invalid responses denote attacks.


Assuntos
Blockchain , Braquiterapia , Consenso , Software , Tecnologia , Segurança Computacional
11.
Radiat Oncol ; 18(1): 13, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36670476

RESUMO

BACKGROUND: The purpose of this work was to obtain the dosimetric parameters of the new GZP3 60Co high-dose-rate afterloading system launched by the Nuclear Power Institute of China, which is comprised of two different 60Co sources. METHODS: The Monte Carlo software Geant4 and EGSnrc were employed to derive accurate calculations of the dosimetric parameters of the new GZP3 60Co brachytherapy source in the range of 0-10 cm, following the formalism proposed by American Association of Physicists in Medicine reports TG43 and TG43U1. Results of the two Monte Carlo codes were compared to verify the accuracy of the data. The source was located in the center of a 30-cm-radius theoretical sphere water phantom. RESULTS: For channels 1 and 2 of the new GZP3 60Co afterloading system, the results of the dose-rate constant (Λ) were 1.115 cGy h-1 U-1 and 1.112 cGy h-1 U-1, and for channel 3 they were 1.116 cGy h-1 U-1 and 1.113 cGy h-1 U-1 according to the Geant4 and EGSnrc, respectively. The radial dose function in the range of 0.25-10.0 cm in a longitudinal direction was calculated, and the fitting formulas for the function were obtained. The polynomial function for the radial dose function and the anisotropy function (1D and 2D) with a [Formula: see text] of 0°-175° and an r of 0.5-10.0 cm were obtained. The curves of the radial function and the anisotropy function fitted well compared with the two Monte Carlo software. CONCLUSION: These dosimetric data sets can be used as input data for TPS calculations and quality control for the new GZP3 60Co afterloading system.


Assuntos
Braquiterapia , Radiometria , Humanos , Dosagem Radioterapêutica , Radiometria/métodos , Software , Radioisótopos de Cobalto , Método de Monte Carlo , Braquiterapia/métodos , Anisotropia
12.
Artigo em Inglês | MEDLINE | ID: mdl-36673855

RESUMO

As COVID-19 spread throughout the world, the hospitality and tourism sectors were hard hit as no other industry. For this reason, the UNWTO developed the One Planet Vision as a response to a sustainable recovery of the tourism sector. At present, when people are starting to travel and stay at hotels again, it is important to analyze what their expectations are of hotels to move forward in the post-pandemic era. For instance, empirical research has been developed to examine people's sentiments toward servicescapes, and a comparative study is presented between 2020 and 2022. Findings contribute to the research by identifying new servicescape attributes during a health crisis. These also lead to practical implications by proposing a scale to evaluate customers' perceptions and to increase their wellbeing and resilience. The current research is one of the first studies to collaborate with the One Planet Vision by empirically proposing improvements in the servicescapes of hotels for a responsible recovery.


Assuntos
Braquiterapia , COVID-19 , Humanos , COVID-19/epidemiologia , Pandemias/prevenção & controle , Pesquisa Empírica , Indústrias
13.
Artigo em Inglês | MEDLINE | ID: mdl-36673907

RESUMO

Because COVID-19 is a respiratory and cardiovascular disease, understanding behaviors that impact cardiopulmonary health, such as tobacco use, is particularly important. While early studies suggested no change in prevalence of tobacco use as COVID-19 emerged, pandemic fatigue, shifting levels of COVID-19 transmission, and vaccine availability have all changed since the start of the pandemic. The current study examined whether time, COVID-19 surges, and/or vaccination status were associated with likelihood of daily and non-daily tobacco use over the first 24 months of the pandemic. Data were obtained from electronic health records of healthcare visits (n = 314,787) to four Southern California VA healthcare systems. Multinomial logistic regression analyses indicated that the likelihood of reporting both daily and non-daily tobacco use (versus non-use) increased over time. Daily and non-daily tobacco use were less common at visits that occurred during COVID-19 surges, as well as among veterans vaccinated against COVID-19. Our findings provide new insight into changes of tobacco use patterns and correlates across the first two years of this pandemic, and understanding these associations may facilitate understanding of health-related behaviors and inform clinical treatment of tobacco use disorder during the COVID-19 pandemic.


Assuntos
Braquiterapia , COVID-19 , Humanos , Pandemias , COVID-19/epidemiologia , Uso de Tabaco/epidemiologia , Vacinação
14.
Int J Mol Sci ; 24(2)2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36674882

RESUMO

We present a method of microstructure fabrication on the tip of the optical fiber using a UV soft-imprint process of polymerizable ionic liquid-based optical resist. Ionic liquid with two UV-sensitive vinylbenzyl groups in the structure was diluted in non-hazardous propylene glycol (PG) to obtain liquid material for imprinting. No additional organic solvent was required. The impact of propylene glycol amount and exposure dose on optical and mechanical properties was investigated. The final procedure of the UV imprint on the optical fiber tip was developed, including the mold preparation, setup building, UV exposure and post-laser cure. As the IL-containing vinylbenzyl groups can also be polymerized by the radical rearrangement of double bonds through thermal heating, the influence of the addition of 1-2% BHT polymerization inhibitor was verified. As a result, we present the fabricated diffraction gratings and the optical fiber spectrometer component-grism (grating-prism), which allows obtaining a dispersion spectrum at the output of an optical in line with the optical fiber long axis, as the main component in an optical fiber spectrometer. The process is very simple due to the fact that its optimization already starts in the process of molecule design, which is part of the trend of sustainable technologies. The final material can be designed by the tailoring of the anion and/or cation molecule, which in turn can lead to a more efficient fabrication procedure and additional functionalities of the final structure.


Assuntos
Braquiterapia , Líquidos Iônicos , Dispositivos Ópticos , Fibras Ópticas , Propilenoglicol
15.
Sci Rep ; 13(1): 1713, 2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36720970

RESUMO

COVID-19 is known to be a cause of microvascular disease imputable to, for instance, the cytokine storm inflammatory response and the consequent blood coagulation. In this study, we propose a methodological approach for assessing the COVID-19 presence and severity based on Random Forest (RF) and Support Vector Machine (SVM) classifiers. Classifiers were applied to Heart Rate Variability (HRV) parameters extracted from photoplethysmographic (PPG) signals collected from healthy and COVID-19 affected subjects. The supervised classifiers were trained and tested on HRV parameters obtained from the PPG signals in a cohort of 50 healthy subjects and 93 COVID-19 affected subjects, divided into two groups, mild and moderate, based on the support of oxygen therapy and/or ventilation. The most informative feature set for every group's comparison was determined with the Least Absolute Shrinkage and Selection Operator (LASSO) technique. Both RF and SVM classifiers showed a high accuracy percentage during groups' comparisons. In particular, the RF classifier reached 94% of accuracy during the comparison between the healthy and minor severity COVID-19 group. Obtained results showed a strong capability of RF and SVM to discriminate between healthy subjects and COVID-19 patients and to differentiate the two different COVID-19 severity. The proposed method might be helpful for detecting, in a low-cost and fast fashion, the presence and severity of COVID-19 disease; moreover, these reasons make this method interesting as a starting point for future studies that aim to investigate its effectiveness as a possible screening method.


Assuntos
Braquiterapia , COVID-19 , Humanos , COVID-19/diagnóstico , Frequência Cardíaca , Coagulação Sanguínea , Síndrome da Liberação de Citocina
16.
Sci Rep ; 13(1): 1783, 2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36720979

RESUMO

Severe hyponatremia can cause life-threatening cerebral edema. Treatment comprises rapid elevation of serum sodium concentration; however, overcorrection can result in osmotic demyelination. This study investigated potential factors, including predictive correction based on the Edelman equation, associated with appropriate correction in 221 patients with a serum sodium concentration ≤ 120 mEq/L who were admitted to a hospital in Nagoya, Japan. Appropriate correction was defined as an elevation in serum sodium concentration in the range of 4-10 mEq/L in the first 24 h and within 18 mEq/L in the first 48 h after the start of the correction. Appropriate corrections were made in 132 (59.7%) of the 221 patients. Multivariate analysis revealed that predictive correction with an infusate and fluid loss formula derived from the Edelman equation was associated with appropriate correction of serum sodium concentration (adjusted odds ratio, 7.84; 95% confidence interval, 2.97-20.64). Relative without its use, the predictive equation results in a lower proportion of undercorrection (14.3% vs. 48.0%, respectively) and overcorrection (1.0% vs. 12.2%, respectively). These results suggest that predictive correction of serum sodium concentrations using the formula derived from the Edelman equation can play an essential role in the appropriate management of patients with severe hyponatremia.


Assuntos
Braquiterapia , Edema Encefálico , Hiponatremia , Humanos , Hiponatremia/terapia , Sódio , Terapia Comportamental
17.
J Dtsch Dermatol Ges ; 21(1): 35-41, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36657038

RESUMO

BACKGROUND AND OBJECTIVE: Radiotherapy of elderly, frail patients with facial skin cancer in proximity to critical organs is challenging. This is the first report on clinical experience with facial skin cancer treated by individualized 3D-printer-based mold high-dose-rate (HDR) brachytherapy (BT). PATIENTS AND METHODS: Fifteen patients not eligible for radical surgery or definitive external beam radiotherapy (EBRT) were treated with 3D-printer-based mold HDR-BT. Patient selection and treatment were in accordance with multidisciplinary tumor board recommendations. Clinical response, toxicity and cosmesis were analyzed. RESULTS: Median age was 77 years. Histology revealed squamous cell carcinoma in seven, basal cell carcinoma in five, melanoma in situ in one, Lentigo maligna in one, and melanoma in one patient, respectively. Median prescription dose was 39 Gy delivered in once-daily fractions of 3 Gy. After a median follow-up of 12.2 months, local recurrence was observed in one patient with melanoma in situ. Apart from one grade 4 cataract, no other > grade 2 late toxicity was documented. CONCLUSIONS: HDR-BT with 3D-printer-based molds for facial skin cancer is a well-tolerated and safe treatment option for elderly, frail patients not eligible for radical surgery or definitive EBRT due to functional inoperability or tumor location.


Assuntos
Braquiterapia , Melanoma , Neoplasias Cutâneas , Humanos , Idoso , Braquiterapia/efeitos adversos , Neoplasias Cutâneas/radioterapia , Neoplasias Cutâneas/etiologia , Melanoma/radioterapia , Melanoma/etiologia , Impressão Tridimensional , Dosagem Radioterapêutica
18.
PLoS One ; 18(1): e0279758, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36626367

RESUMO

Unlike the Carnot heat engine efficiency published in 1824, an isothermal efficiency derived from thermodynamics and information theory can be applied to biological systems. The original approach by Pierce and Cutler in 1959 to derive the isothermal efficiency equation came from Shannon's channel capacity of 1949 and from Felker's 1952 determination of the minimum energy dissipation needed to gain a bit. In 1991 and 2010 Schneider showed how the isothermal efficiency equation can be applied to molecular machines and that this can be used to explain why several molecular machines are 70% efficient. Surprisingly, some macroscopic biological systems, such as whole ecosystems, are also 70% efficient but it is hard to see how this could be explained by a thermodynamic and molecular theory. The thesis of this paper is that the isothermal efficiency can be derived without using thermodynamics by starting from a set of independent Gaussian distributions. This novel derivation generalizes the isothermal efficiency equation for use at all levels of biology, from molecules to ecosystems.


Assuntos
Braquiterapia , Ecossistema , Distribuição Normal , Termodinâmica , Teoria da Informação
19.
Sci Rep ; 13(1): 509, 2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36627400

RESUMO

Projects are characterised by activity networks with a critical path, a sequence of activities from start to end, that must be finished on time to complete the project on time. Watching over the critical path is the project manager's strategy to ensure timely project completion. This intense focus on a single path contrasts the broader complex structure of the activity network, and is due to our poor understanding on how that structure influences this critical path. Here, we use a generative model and detailed data from 77 real world projects (+ $10 bn total budget) to demonstrate how this network structure forces us to look beyond the critical path. We introduce a duplication-split model of project schedules that yields (i) identical power-law in- and-out degree distributions and (ii) a vanishing fraction of critical path activities with schedule size. These predictions are corroborated in real projects. We demonstrate that the incidence of delayed activities in real projects is consistent with the expectation from percolation theory in complex networks. We conclude that delay propagation in project schedules is a network property and it is not confined to the critical path.


Assuntos
Braquiterapia , Orçamentos
20.
Zhonghua Yi Xue Za Zhi ; 103(3): 199-204, 2023 Jan 17.
Artigo em Chinês | MEDLINE | ID: mdl-36649991

RESUMO

Objective: According to the formula provided by the TG43 report [AAPM TG43 (2004)] proposed by the American Association of Physicists in Medicine (AAPM) in 2004, we calculated the dose distribution around the radioactive iodine-125 particles, and verified the calculation accuracy of the radioactive iodine-125 particles treatment planning system. Methods: AAPM TG43 (2004) report provides two calculation methods when calculating the dose around a single radioactive source. The calculation method that does not consider the geometric structure of the radioactive source is called point source calculation method, and the calculation method that considers the geometric structure of the radioactive source is called line source calculation method. Assuming a single Amersham 6711 radioactive iodine-125 particle with an activity of 100 U, the following point doses were calculated according to the two calculation methods provided by AAPM TG43 (2004) report, at 0°, 90° directions, distances 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5 and 6 cm; In the direction of 45°, the doses at 0.71, 1.41, 2.12, 2.83, 3.54, 4.24, 4.95, 5.66, 6.36, 7.07, 7.78 and 8.49 cm. On the clinically used brachytherapy planning system variseeds 8.0, the above two calculation methods are used to calculate the corresponding activity and the dose around the corresponding type of radioactive iodine-125 particles, and the function of capturing points to templates built in the planning system is used to accurately find the above corresponding point position, using a single measurement of the above corresponding point dose; and comparation of the results were performed to see if there is a statistical difference. Results: The AAPM TG43 report uses point source calculation method to calculate the dose of single Amersham 6711 radioactive iodine-125 particles with activity of 100 U at 0° and 90° directions. The points with the same distance and the same dose are 8 082.18, 1 870.08, 756.58, 381.47, 217.11, 131.91, 86.55, 58.32, 39.97, 27.42, 19.74, 14.13 Gy, respectively, at 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5 and 6 cm away from them. In the 45° direction, the doses at the distances of 0.71, 1.41, 2.12, 2.83, 3.54, 4.24, 4.95, 5.66, 6.36, 7.07, 7.78 and 8.49 cm are 3 957.37, 865.83, 329.99, 155.69, 84.10, 48.50, 28.49, 17.80, 11.37, 7.38, 4.98 and 3.39 Gy, respectively; For line source calculation method, radioactive particles are at the same distance as above. The doses at each point in the direction of 0° are 3 128.71, 755.44, 330.30, 180.53, 107.74, 68.56, 46.40, 32.22, 22.70, 16.00, 11.51, 8.24 Gy, respectively. The doses at each point in the direction of 90° are 8 306.46, 1 981.01, 802.74, 405.38, 230.60, 140.03, 91.83, 61.84, 42.36, 29.05, 20.91, 14.97 Gy; In the 45° direction, the dose at the corresponding distance as above is 4 020.78, 877.43, 333.49, 156.93, 84.69, 48.81, 28.65, 17.89, 11.42, 7.41, 4.99 and 3.40 Gy, respectively. The maximum dose difference (0.3%) between the two methods is 7.78 cm in the 45° direction, the maximum difference (-0.3%) between the two methods is 8.49 cm in the 45° direction, and the value of other sampling points is less than 0.3%. The closer the Amersham 6711 iodine-125 particles are to the source in the directions of 0°, 45°, and 90°, the faster the dose will drop, and the dose will drop gradually as the distance increases. Conclusion: The brachytherapy planning system variseeds 8.0 and the AAPM TG43 report calculate a maximum dose difference of 0.3%, which can accurately calculate the dose distribution around radioactive iodine-125 seeds, and provide a reliable tool for the clinical implementation of radioactive iodine-125 particles implantation for tumor treatment.


Assuntos
Braquiterapia , Neoplasias da Glândula Tireoide , Humanos , Radioisótopos do Iodo , Dosagem Radioterapêutica , Método de Monte Carlo , Planejamento da Radioterapia Assistida por Computador/métodos , Radiometria/métodos
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