scholarly journals Robustness assessment of a novel 4D optimization approach for lung cancer radiotherapy

2021 ◽  
Author(s):  
Shahad M. Al-Ward

One of the main challenges to treatment of lung cancer with radiation therapy is the tumor motion due to respiration. Previously, a novel approach was developed to generate treatment plans which compensate for respiratory motion and its variations. The worst case method is based on combining two intensity maps from two 4D plans optimized on the two worst cases of motion variations. The worst case planning method was previously tested on simulated motion variations. The goal of this project was to further test the worst case approach on realistic patient motion variations and treatment planning data. Two approaches to combining worst case plans were investigated: the first method takes the average of the two intensity maps, and the second method takes the maximum intensity of the two intensity maps. The robustness of worst case plans was compared with ITV plans and nominal 4D plans on three different motion variation scenarios. Study 1 and 2 investigated the robustness of the worst case methods on amplitude variations and patient motion variations on simulated image data. Study 3 investigated the robustness of the worst case methods on patient motion variations using real patient image data. The average intensity worst case method was only robust to Study 3 motion variations. The maximum intensity worst case method, the margin based, and the nominal approaches were not robust to any of the motion variations. Further evaluation over a wide range of tumour sizes, motion amplitudes and variability is required to determine the clinical applicability of the worst case planning method.

2021 ◽  
Author(s):  
Shahad M. Al-Ward

One of the main challenges to treatment of lung cancer with radiation therapy is the tumor motion due to respiration. Previously, a novel approach was developed to generate treatment plans which compensate for respiratory motion and its variations. The worst case method is based on combining two intensity maps from two 4D plans optimized on the two worst cases of motion variations. The worst case planning method was previously tested on simulated motion variations. The goal of this project was to further test the worst case approach on realistic patient motion variations and treatment planning data. Two approaches to combining worst case plans were investigated: the first method takes the average of the two intensity maps, and the second method takes the maximum intensity of the two intensity maps. The robustness of worst case plans was compared with ITV plans and nominal 4D plans on three different motion variation scenarios. Study 1 and 2 investigated the robustness of the worst case methods on amplitude variations and patient motion variations on simulated image data. Study 3 investigated the robustness of the worst case methods on patient motion variations using real patient image data. The average intensity worst case method was only robust to Study 3 motion variations. The maximum intensity worst case method, the margin based, and the nominal approaches were not robust to any of the motion variations. Further evaluation over a wide range of tumour sizes, motion amplitudes and variability is required to determine the clinical applicability of the worst case planning method.


2020 ◽  
Author(s):  
Evalien Veldhuijzen ◽  
Iris Walraven ◽  
Jose Belderbos

BACKGROUND The Patient Reported Outcomes Version of the Common Terminology Criteria of Adverse Events (PRO-CTCAE) item library covers a wide range of symptoms relevant for oncology care. To enable implementation of PRO-CTCAE-based symptom monitoring in clinical practice, there is a need to select a subset of items relevant for specific patient populations. OBJECTIVE The aim of this study was to develop a PRO-CTCAE subset relevant for patients with lung cancer. METHODS The PRO-CTCAE-based subset for lung cancer patients was generated using a mixed methods approach based on the European Organization for Research and Treatment of Cancer (EORTC) guidelines for developing questionnaires, consisting of a literature review and semi-structured interviews with both lung cancer patients and health care practitioners (HCPs). Both patients and HCPs were queried on the relevance and impact of all PRO-CTCAE items. Results were summarized and, after a final round of expert review, a selection of clinically relevant items for lung cancer patients was made. RESULTS A heterogeneous group of lung cancer patients (n=25) from different treatment modalities and HCPs (n=22) participated in the study. A final list of eight relevant PRO-CTCAE items was created: decreased appetite, cough, shortness of breath, fatigue, constipation, nausea, sadness, and pain (general). CONCLUSIONS Based on literature and both professional and patient input, a subset of PRO-CTCAE items has been identified for use in lung cancer patients in clinical practice. Future work is needed to confirm the validity and effectiveness of this PRO-CTCAE lung cancer subset internationally, and in the real-world clinical practice setting.


2020 ◽  
pp. 1-10
Author(s):  
Bryce J. Dietrich

Abstract Although previous scholars have used image data to answer important political science questions, less attention has been paid to video-based measures. In this study, I use motion detection to understand the extent to which members of Congress (MCs) literally cross the aisle, but motion detection can be used to study a wide range of political phenomena, like protests, political speeches, campaign events, or oral arguments. I find not only are Democrats and Republicans less willing to literally cross the aisle, but this behavior is also predictive of future party voting, even when previous party voting is included as a control. However, this is one of the many ways motion detection can be used by social scientists. In this way, the present study is not the end, but the beginning of an important new line of research in which video data is more actively used in social science research.


Healthcare ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 778
Author(s):  
Ann-Rong Yan ◽  
Indira Samarawickrema ◽  
Mark Naunton ◽  
Gregory M. Peterson ◽  
Desmond Yip ◽  
...  

Venous thromboembolism (VTE) is a significant cause of mortality in patients with lung cancer. Despite the availability of a wide range of anticoagulants to help prevent thrombosis, thromboprophylaxis in ambulatory patients is a challenge due to its associated risk of haemorrhage. As a result, anticoagulation is only recommended in patients with a relatively high risk of VTE. Efforts have been made to develop predictive models for VTE risk assessment in cancer patients, but the availability of a reliable predictive model for ambulate patients with lung cancer is unclear. We have analysed the latest information on this topic, with a focus on the lung cancer-related risk factors for VTE, and risk prediction models developed and validated in this group of patients. The existing risk models, such as the Khorana score, the PROTECHT score and the CONKO score, have shown poor performance in external validations, failing to identify many high-risk individuals. Some of the newly developed and updated models may be promising, but their further validation is needed.


Author(s):  
P.G Young ◽  
T.B.H Beresford-West ◽  
S.R.L Coward ◽  
B Notarberardino ◽  
B Walker ◽  
...  

Image-based meshing is opening up exciting new possibilities for the application of computational continuum mechanics methods (finite-element and computational fluid dynamics) to a wide range of biomechanical and biomedical problems that were previously intractable owing to the difficulty in obtaining suitably realistic models. Innovative surface and volume mesh generation techniques have recently been developed, which convert three-dimensional imaging data, as obtained from magnetic resonance imaging, computed tomography, micro-CT and ultrasound, for example, directly into meshes suitable for use in physics-based simulations. These techniques have several key advantages, including the ability to robustly generate meshes for topologies of arbitrary complexity (such as bioscaffolds or composite micro-architectures) and with any number of constituent materials (multi-part modelling), providing meshes in which the geometric accuracy of mesh domains is only dependent on the image accuracy (image-based accuracy) and the ability for certain problems to model material inhomogeneity by assigning the properties based on image signal strength. Commonly used mesh generation techniques will be compared with the proposed enhanced volumetric marching cubes (EVoMaCs) approach and some issues specific to simulations based on three-dimensional image data will be discussed. A number of case studies will be presented to illustrate how these techniques can be used effectively across a wide range of problems from characterization of micro-scaffolds through to head impact modelling.


Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 621
Author(s):  
Fakhara Sabir ◽  
Maimoona Qindeel ◽  
Mahira Zeeshan ◽  
Qurrat Ul Ain ◽  
Abbas Rahdar ◽  
...  

Lung cancer is among the most prevalent and leading causes of death worldwide. The major reason for high mortality is the late diagnosis of the disease, and in most cases, lung cancer is diagnosed at fourth stage in which the cancer has metastasized to almost all vital organs. The other reason for higher mortality is the uptake of the chemotherapeutic agents by the healthy cells, which in turn increases the chances of cytotoxicity to the healthy body cells. The complex pathophysiology of lung cancer provides various pathways to target the cancerous cells. In this regard, upregulated onco-receptors on the cell surface of tumor including epidermal growth factor receptor (EGFR), integrins, transferrin receptor (TFR), folate receptor (FR), cluster of differentiation 44 (CD44) receptor, etc. could be exploited for the inhibition of pathways and tumor-specific drug targeting. Further, cancer borne immunological targets like T-lymphocytes, myeloid-derived suppressor cells (MDSCs), tumor-associated macrophages (TAMs), and dendritic cells could serve as a target site to modulate tumor activity through targeting various surface-expressed receptors or interfering with immune cell-specific pathways. Hence, novel approaches are required for both the diagnosis and treatment of lung cancers. In this context, several researchers have employed various targeted delivery approaches to overcome the problems allied with the conventional diagnosis of and therapy methods used against lung cancer. Nanoparticles are cell nonspecific in biological systems, and may cause unwanted deleterious effects in the body. Therefore, nanodrug delivery systems (NDDSs) need further advancement to overcome the problem of toxicity in the treatment of lung cancer. Moreover, the route of nanomedicines’ delivery to lungs plays a vital role in localizing the drug concentration to target the lung cancer. Surface-modified nanoparticles and hybrid nanoparticles have a wide range of applications in the field of theranostics. This cross-disciplinary review summarizes the current knowledge of the pathways implicated in the different classes of lung cancer with an emphasis on the clinical implications of the increasing number of actionable molecular targets. Furthermore, it focuses specifically on the significance and emerging role of surface functionalized and hybrid nanomaterials as drug delivery systems through citing recent examples targeted at lung cancer treatment.


2000 ◽  
Author(s):  
Emiliano Cioffarelli ◽  
Enrico Sciubba

Abstract A hybrid propulsion system of new conception for medium-size passenger cars is described and its preliminary design developed. The system consists of a turbogas set operating at fixed rpm, and a battery-operated electric motor that constitutes the actual “propulsor”. The battery pack is charged by the thermal engine which works in an electronically controlled on/off mode. Though the idea is not entirely new (there are some concept cars with similar characteristics), the present study has important new aspects, in that it bases the sizing of the thermal engine on the foreseen “worst case” vehicle mission (derived from available data on mileage and consumption derived from road tests and standard EEC driving mission cycles) that they can in fact be accomplished, and then proceeds to develop a control strategy that enables the vehicle to perform at its near–peak efficiency over a wide range of possible missions. To increase the driveability of the car, a variable-inlet vane system is provided for the gas turbine. After developing the mission concept, and showing via a thorough set of energy balances (integrated over various mission profiles), a preliminary sizing of the turbogas set is performed. The results of this first part of the development program show that the concept is indeed feasible, and that it has important advantages over both more traditional (Hybrid Vehicles powered by an Internal Combustion Engine) and novel (All-Electric Vehicle) propulsion systems.


2015 ◽  
Vol 53 (3) ◽  
pp. 477-486 ◽  
Author(s):  
Elke Zuern

South Africa is at a crossroads. The state has not adequately addressed dire human development needs, often failing to provide the services it constitutionally guarantees. As a result, citizens are expressing their frustrations in a variety of ways, at times including violence. These serious challenges are most readily apparent in poverty, inequality and unemployment statistics, but also in electricity provision, billing and affordability as well as a recent spate of racially motivated attacks which highlight the tension both among South Africans and between South Africans and darker skinned foreigners. The country has, however, been on the brink before and avoided the worst-case scenario of full-scale civil war and state collapse. Far too often South Africa's past successes have been attributed to the role of one man, Nelson Mandela. While Mandela was indeed an extraordinary human being who rightly deserved the international awards and accolades as well as the deep admiration of so many, South Africa's triumphs as a society and a state are the product of both cooperative and conflicting contributions by a wide range of actors. A central question at the present juncture is how well equipped domestic actors and institutions are to address the crisis. The following pages seek to provide some insights and through the perspectives of three authors to consider causes and possible responses.


Author(s):  
A. V. Laryukov ◽  
E. K. Laryukova ◽  
M. K. Mikhailov

Objective:сonstructive principles development of early diagnosis of bone and cerebral metastases of peripheral non-small cell lung cancer (PNSCLC), is based on the targeted preventive and personalized application of radiological and nuclear diagnostic methods.Materials and methods.There was performed the retrospective analysis of medical cards of 1473 patients with peripheral non-small cell lung cancer for the evaluation of the characteristics and frequency of bones and brain metastases. The frequency and features of bone and brain metastases depending on clinical and morphological features of the primary lung tumor were studied. 118 patients with PNSCLC with bone and brain metastases, regardless of clinical symptoms, were examined using a wide range of modern radiological and nuclear methods.Conclusion:the original algorithm has been developed on the study of the diagnostic significance of medical imaging methods. The application of this algorithm will significantly improve the early diagnosis of bone and cerebral metastases and improve the staging of PNSCLC.


2020 ◽  
Author(s):  
Hui Liu ◽  
Xiaobo Wang ◽  
Ouyang Jin ◽  
Denggang Fu ◽  
You Peng ◽  
...  

Abstract Background: Daidzein is one of the key bioactive substances of soybean isoflavones that has a wide range of health benefits includes antineoplastic. Epidemiological evidence suggests that soy glycogen is associated with the incidence and prognosis of lung cancer. we purposed to assess the effect and molecular mechanism of daidzein on lung cancer, and to maximize therapy outcome for individualized treatment. Methods: In this report, H1299 were cultured in a medium with 10 μM daidzein for 6 hours , we detected the expression level of apoptosis-related genes in H1299 by cDNA microarray analysis. The selected genes were further validated by using RT-PCR analysis and Western blot. Finally, We usedflow cytometry to detect cell cycle alterations, and apoptosis the proliferation and apoptosis in HELF and H1299 cells were detected by Cell counting kit-8 assays. Results: These results indicate that low concentrations of isoflavone crude extract and daidzein could significantly affect the proliferation of H1299 (Human lung adenocarcinoma) and HELF (Human embryonic lung fibroblast) cells. The results of microarray in our study suggest that apoptosis-related genes are up-regulated induced by daidzein in H1299 cells and verified by RT-qPCR, particularly TP53 and caspase9. Western blotting shows the effect of daidzein on P53 and caspase9 in HELF cells be more obvious than it in H1299 cells. While the expression of TP53 was suppressed by pifithrin-α (PFTα) in HELF and H1299 cells, the mRNA and protein expression of TP53 still increase induced by daidzein, also, the effect of apoptosis induced by daidzein is involved in the P53 apoptosis pathway through inhibition of TP53 gene expression by PFTα. Conclusions: In conclusion, daidzein affected proliferation and apoptosis in HELF and H1299 cells, and the mechanism of apoptosis involved in the P53 signaling pathway.


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