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Multiscale In Silico Modeling of Cartilage Injuries

Injurious loading of the joint can be accompanied by articular cartilage damage and trigger inflammation. However, it is not well-known which mechanism controls further cartilage degradation, ultimately leading to post-traumatic osteoarthritis. For personalized prognostics, there should also be a method that can predict tissue alterations following joint and cartilage injury. This chapter gives an

Ticagrelor Treatment is Associated With Increased Coronary Flow Reserve in Survivors of Myocardial Infarction

Background: The pleiotropic action of ticagrelor, with effects in addition to platelet inhibition, has been shown to improve endothelial function in patients with coronary artery disease. These positive effects are possibly adenosine mediated. This study investigated the association of ticagrelor therapy and coronary artery flow reserve in survivors of myocardial infarction (MI). Methods: This was

Structures for collaboration and networked adaptation : Emerging themes from the COVID-19 pandemic

The COVID-19 pandemic is a crisis that is "creeping" in its onset and "slow-burning" in its duration. It is characterized by extreme uncertainty, ambiguity, and complexity, presenting an unprecedented need for response across sectors and political-administrative levels. While there has been an explosion of research papers into the national strategies for handling the pandemic, empirical publicatio

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Odeta Rudling analysiert in Von der nationalen Form zum nationalen Inhalt die Ausformung der sowjetischen Folklorepolitik, die zwischen 1940 und 1990 zur Übertragung und partiellen Übernahme des sowjetischen Modells in der litauischen SSR führte. Mit dem Fokus auf lokale Akteure und deren Rolle in diesem Prozess veranschaulicht sie sowohl die Techniken der Eliten als auch die inhaltliche Transform

PET/CT-guided treatment planning for paediatric cancer patients : A simulation study of proton and conventional photon therapy

Objective: To investigate the impact of including fluorine-18 fludeoxyglucose (18F-FDG) positron emission tomography (PET) scanning in the planning of paediatric radiotherapy (RT). Methods: Target volumes were first delineated without and subsequently re-delineated with access to 18F-FDG PET scan information, on duplicate CT sets. RT plans were generated for three-dimensional conformal photon RT (

Patterns and predictors of amelioration of genitourinary toxicity after high-dose intensity-modulated radiation therapy for localized prostate cancer : Implications for defining postradiotherapy urinary toxicity

Background Treatment-related toxicity and quality of life (QoL) considerations are important when counseling patients with localized prostate cancer (PCa). Objective To determine the incidence and longitudinal pattern of late genitourinary (GU) toxicity and QoL after high-dose, intensity-modulated radiotherapy (IMRT). Design, setting, and participants A total of 268 patients with localized PCa wer

Doses to carotid arteries after modern radiation therapy for hodgkin lymphoma : Is stroke still a late effect of treatment?

Purpose Hodgkin lymphoma (HL) survivors are at an increased risk of stroke because of carotid artery irradiation. However, for early-stage HL involved node radiation therapy (INRT) reduces the volume of normal tissue exposed to high doses. Here, we evaluate 3-dimensional conformal radiation therapy (3D-CRT), volumetric-modulated arc therapy (VMAT), and proton therapy (PT) delivered as INRT along w

Real-time dynamic MLC tracking for inversely optimized arc radiotherapy

Background and purpose: Motion compensation with MLC tracking was tested for inversely optimized arc radiotherapy with special attention to the impact of the size of the target displacements and the angle of the leaf trajectory. Materials and methods: An MLC-tracking algorithm was used to adjust the MLC positions according to the target movements using information from an optical real-time positio

Estimated risk of cardiovascular disease and secondary cancers with modern highly conformal radiotherapy for early-stage mediastinal Hodgkin lymphoma

Hodgkin lymphoma (HL) survivors have an increased morbidity and mortality from secondary cancers and cardiovascular disease (CD). We evaluate doses with involved node radiotherapy (INRT) delivered as 3D conformal radiotherapy (3D CRT), volumetric modulated arc therapy (VMAT), or proton therapy (PT), compared with the extensive Mantle Field (MF). Patients and methods: For 27 patients with early-sta

Interaction between the biological effects of high- and low-LET radiation dose components in a mixed field exposure

Purpose: The relative biological effectiveness of two epithermal neutron sources, a reactor based source at Studsvik, Sweden, and a proton accelerator-based source in Birmingham, UK, was studied in relation to the proportional absorbed dose distribution as a function of neutron energy. Evidence for any interactions between the effects of biological damage induced by high- and low-linear energy tra

Early postoperative 18F-FET PET/MRI for pediatric brain and spinal cord tumors

Complete resection is the treatment of choice for most pediatric brain tumors, but early postoperative MRI for detection of residual tumor may be misleading because of MRI signal changes caused by the operation. PET imaging with amino acid tracers in adults increases the diagnostic accuracy for brain tumors, but the literature in pediatric neurooncology is limited. A hybrid PET/MRI system is highl

The effect on esophagus after different radiotherapy techniques for early stage Hodgkin's lymphoma

Introduction. The cure rate of early stage Hodgkin's lymphoma (HL) is excellent; investigating the late effects of treatment is thus important. Esophageal toxicity is a known side effect in patients receiving radiotherapy (RT) to the mediastinum, although little is known of this in HL survivors. This study investigates the dose to the esophagus in the treatment of early stage HL using different RT

Spatially varying Riemannian elasticity regularization : Application to thoracic CT registration in image-guided radiotherapy

For deformable registration of computed tomography (CT) scans in image guided radiation therapy (IGRT) we apply Riemannian elasticity regularization. We explore the use of spatially varying elasticity parameters to encourage bone rigidity and local tissue volume change only in the gross tumor volume (GTV) and the lungs. We evaluate the method on the point-validated 4DCT breathing thorax POPI-model

Dosimetric benefit of DMLC tracking for conventional and sub-volume boosted prostate intensity-modulated arc radiotherapy

This study investigated the dosimetric impact of uncompensated motion and motion compensation with dynamic multileaf collimator (DMLC) tracking for prostate intensity modulated arc therapy. Two treatment approaches were investigated; a conventional approach with a uniform radiation dose to the target volume and an intraprostatic lesion (IPL) boosted approach with an increased dose to a subvolume o

Use of PET/CT instead of CT-only when planning for radiation therapy does not notably increase life years lost in children being treated for cancer

Background: PET/CT may be more helpful than CT alone for radiation therapy planning, but the added risk due to higher doses of ionizing radiation is unknown. Objective: To estimate the risk of cancer induction and mortality attributable to the [F-18]2-fluoro-2-deoxyglucose (FDG) PET and CT scans used for radiation therapy planning in children with cancer, and compare to the risks attributable to t

Artifacts in conventional computed tomography (CT) and free breathing four-dimensional CT induce uncertainty in gross tumor volume determination

Purpose: Artifacts impacting the imaged tumor volume can be seen in conventional three-dimensional CT (3DCT) scans for planning of lung cancer radiotherapy but can be reduced with the use of respiration-correlated imaging, i.e., 4DCT or breathhold CT (BHCT) scans. The aim of this study was to compare delineated gross tumor volume (GTV) sizes in 3DCT, 4DCT, and BHCT scans of patients with lung tumo

A Retrospective Evaluation of the Benefit of Referring Pediatric Cancer Patients to an External Proton Therapy Center

Background: Pediatric cancer patients requiring radiation therapy (RT) have been routinely assessed and referred to proton therapy (PT) at an external institution. The benefit of the delivered PT compared to the state-of-the-art intensity modulated x-ray RT (XT) at the home institution was evaluated. Procedure: Twenty-four consecutive children referred for PT during 2010–2013 for craniospinal (CSI

Photon and proton therapy planning comparison for malignant glioma based on CT, FDG-PET, DTI-MRI and fiber tracking

Purpose. The purpose of this study was to compare treatment plans generated using fixed beam Intensity Modulated photon Radiation Therapy (IMRT), inversely optimized arc therapy (RapidArc(R), RA) with spot-scanned Intensity Modulated Proton Therapy (IMPT) for high-grade glioma patients. Plans were compared with respect to target coverage and sparing of organs at risk (OARs), with special attention

Stability of percutaneously implanted markers for lung stereotactic radiotherapy

The purpose of this study was to evaluate the stability of complex markers implanted into lung tumors throughout a course of stereotactic body radiotherapy (SBRT). Fifteen patients referred for lung SBRT were prospectively included. Radio-opaque markers were implanted percutaneously, guided by computed tomography (CT). Deep inspiration breath-hold CT scans (BHCT) were acquired at planning and on t