Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 29 for “"organs at risk"”.
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Quantifying, Understanding and Predicting Differences Between Planned and Delivered Dose to Organs at Risk in Head & Neck Cancer Patients Undergoing Radical Radiotherapy to Promote Intelligently Targeted Adaptive Radiotherapy
… radiotherapy (RT) is an effective but toxic treatment for head and neck cancer (HNC). Contemporary radiotherapy techniques sculpt dose to target disease and avoid organs at risk (OARs), but anatomical change during treatment mean that the radiation dose delivered to the patient – delivered dose …
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Multicriteria Optimization in Inverse Radiotherapy Planning
The development of intensity-modulated radiotherapy (IMRT) has greatly enhanced the possibilities of shaping the dose distribution. However, because of physical limitations, even with IMRT a certain dose to organs at risk is unavoidable, so in treatment planning often a compromise between different …
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Auto-Segmentation In Pancreatic and Liver Radiation Therapy
… cancers exhibit a high mortality rate compared to other cancer types. Among these, pancreatic cancer ranks as the fourth leading cause of cancer-related deaths worldwide. The five-year survival rate remains alarmingly low at a mere 9%. Hepatocellular carcinoma (HCC), another …
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Evaluation of Timepoint Assessment Schemes for Offline Adaptive Radiotherapy of the Head and Neck Using Velocity
… care for those receiving head and neck cancer treatment by reducing dose to organs at risk (OARs) and allowing margin reduction for targets. Current literature investigates predetermined and triggered adaptation, but how to trigger and how often to assess remain open questions. So, a study of …
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Combining Mathematical Programming and Heuristic Methods to Solve the Multi-Objective Beam Angle Optimisation Problem in Radiation Therapy
… of cancer, either personally or through a relative or friend. Furthermore, cancer is the leading cause of death (28.9 percent) in New Zealand and a major cause of hospitalisation. Although the prevalence of cancer has increased in the last four decades, cancer survival has doubled in the same …
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System Solution for In-Beam Positron Emission Tomography Monitoring of Radiation Therapy
… is a system for monitoring high precision radiation therapy which is in the most cases applied to the tumors near organs at risk. High quality and fast availability of in-beam PET images are, therefore, extremely important for successful verification of the dose delivery. Two main problems make …
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Construction of a model for the improved planning of MCO-informed VMAT in RayStation using a knowledge base of clinical IMRT-MCO treatment plans
Intensity Modulated Radiation Therapy (IMRT) is a type of external beam radiation therapy that has proven effective at treating many cancers. A related therapy type, Volumetric Modulated Arc Therapy (VMAT), has the potential to provide comparable dose coverage to tumor sites while better sparing …
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Volumetric modulated Arc Therapy versus 3D conformal radiotherapy in the treatment of locally advanced cervical cancer. A single institution, comparative dosimetric study
… advanced cervical cancer (LACC). Generally, VMAT is thought to achieve higher conformity to the Planned Target Volume (PTV) and better sparing of organs at risk (OAR) when compared to 3D-CRT. This study focused on these principles as it applied to treatment and potential toxicity in the …
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Towards patient selection for cranial proton beam therapy – Assessment of current patient-individual treatment decision strategies
… to conventional photon radiotherapy. Those patients who are supposed to experience the greatest reduction in side effects should preferably be treated with proton beam therapy. One option for this patient selection is the model-based approach. Its feasibility in patients with intracranial …
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CHARACTERIZATION OF BREAST RT TREATMENT BY MULTI-INSTITUTIONAL AI-KNOWLEDGE-BASED PLANNING OPTIMIZATION MODELS
… intelligence to predict dose distribution to Organs at Risk, particularly the heart, in breast cancer radiotherapy. The goal is to enable physicists to quickly assess, via computed tomography (CT), whether a tangential field plan is adequate or if alternative techniques, such as breath-hold CT …
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Treatment planning for manifold multi-ion particle therapy
Conventional charged particle radiation therapy systems utilise a single charged particle species to deliver a therapeutic radiation dose to the target - most commonly protons or carbon ions. While such radiation therapy is highly effective for the treatment of many cancers, there is growing …
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Novel image processing and deep learning methods for head and neck cancer delineation from MRI data
Intensity modulated radiation treatment aims to achieve accurate treatment of cancer without introducing damage and side effects to organs at risk (OAR). Development of medical imaging technique enables molecular study of cancer to provide quantitative analysis and three-dimensional visualisation …
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DOSE-BASED EVALUATION OF A PROSTATE BED PROTOCOL
<p>The image-guided radiation therapy (IGRT) protocol used at Juravinski Cancer Center for post-prostatectomy patients involves acquiring a kV cone beam computed tomography (CBCT) image at each fraction and shifting the treatment couch to align surgical clips. This IGRT strategy is promising but …
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Monitoring Material Modification using Inline Coherent Imaging
Laser machining is a commonly used method for materials processing. Focusing laser energy onto a sample can lead to material modifications and achieve feature sizes on the order of micrometres. However, designing a machining platform capable of producing high quality, repeatable, and accurate …
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Development of a Breathing Monitor and Training System, And the Analysis of Methods of Training Patients to Regulate their Breathing when Undergoing Radiotherapy for Lung cancer
Purpose: Advanced radiotherapy treatments for Non-Small-Cell Lung Cancer (NSCLC) rely on conforming the radiation dose to the tumour geometry as tightly as possible; this increases the probability of killing the tumour cells while simultaneously reducing the radiation dose to nearby tissues and to …
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Improving Quantitative Treatment Response Monitoring With Deformable Image Registration
Quantitative imaging with 18F-FDG PET/CT has the potential to provide an in vivo assessment of response to radiotherapy (RT). However, comparing tissue tracer uptake in longitudinal studies is often confounded by variations in patient setup and potential treatment induced gross anatomic changes. …
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Modelling Uncertainties in Radiation Therapy: The Clinical Impact on Prostate Bed Treatment
… techniques in radiotherapy, including IMRT and VMAT offer methods to deliver highly conformal dose distributions to the target while sparing dose to organs at risk. However, these techniques are highly complex and therefore raise the potential for errors in radiotherapy planning and delivery. This …
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Head and Neck Cancer Offline Adaptive Radiotherapy Proof-of-Concept Workflow for Low-Resource Clinics Utilizing NTCP
… potential to improve head and neck (H&N) cancer patient outcomes by creating new treatment plan(s) throughout the treatment regimen, reducing dose to nearby organs at risk (OAR) whenever possible. While online ART makes use of specific and costly machinery to create daily treatment plans for …
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Using deep learning generated CBCT contours for on-line dose assessment of prostate SABR treatments
Prostate Stereotactic Ablative Body Radiotherapy (SABR) is a hypofractionated treatment regime where small errors in patient setup have the potential to deliver much higher doses to Organs at Risk (OARs). Inter-fraction variability is reduced by having patients follow a bowel and bladder …
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