3D Printing Planning Stereotactic Radiosurgery in Uveal Melanoma Patients

The aim of our work is to use a new modality for visualization of intraocular tumors in three-dimensional space for planning of stereotactic radiosurgery procedure on linear accelerator. Malignant uveal melanoma is the most common malignant tumor of the inner eye structures in adults. Stereotactic radiosurgery on linear accelerator is the method of treatment that requires precise planning. However, in some cases, it is very difficult to imagine the structures based only on fusion of two-dimensional computed tomography (CT) and magnetic resonance imaging (MRI) scans. For the team of specialists planning the procedure, 3D printed models represent the way how to perceive the real shape of the tumor and its location considering the important structures of the eye globe. By using the open-source software for segmentation (3D Slicer), we created a virtual 3D model of the eye globe with a tumor that utilized tissue density information based on CT and/or MRI dataset. By creating and introducing a new imaging modality for tumor visualization, we provided real 3D model of the eye globe for the specialists that enabled them more effective planning of the stereotactic radiosurgery

Towards a cyber physical system for personalised and automatic OSA treatment

Obstructive sleep apnea (OSA) is a breathing disorder that takes place in the course of the sleep and is produced by a complete or a partial obstruction of the upper airway that manifests itself as frequent breathing stops and starts during the sleep. The real-time evaluation of whether or not a patient is undergoing OSA episode is a very important task in medicine in many scenarios, as for example for making instantaneous pressure adjustments that should take place when Automatic Positive Airway Pressure (APAP) devices are used during the treatment of OSA. In this paper the design of a possible Cyber Physical System (CPS) suited to real-time monitoring of OSA is described, and its software architecture and possible hardware sensing components are detailed. It should be emphasized here that this paper does not deal with a full CPS, rather with a software part of it under a set of assumptions on the environment. The paper also reports some preliminary experiments about the cognitive and learning capabilities of the designed CPS involving its use on a publicly available sleep apnea database

Performance study of Kalman Filter track reconstruction algorithms in the FOOT experiment

Il progresso tecnologico ha portato all'evoluzione delle tecniche di radiazione oncologica, tra cui spicca il trattamento di adroterapia, che utilizza particelle cariche come protoni e ioni C. Il vantaggio rispetto alla radioterapia convenzionale, è la peculiare curva di rilascio di dose di particelle cariche nei tessuti, che presenta un massimo localizzato (picco di Bragg) alla fine del cammino. L'obiettivo di un trattamento adroterapico è la localizzazione della massima dose nel volume tumorale con minimo rilascio di dose nei tessuti sani circostanti. Oggigiorno, il Treatment Planning System (TPS) non considera appieno gli eventi di frammentazione, sia del bersaglio di materia organica nel caso di fasci di protoni, sia del proiettile in caso di ioni pesanti. Questo può portare alla sottostima della dose rilasciata negli organi a rischio, compromettendo l'efficacia del trattamento. Il nuovo esperimento FOOT (FragmentatiOn Of Target) si incarica di ricavare dati sperimentali sulla sezione d'urto dei frammenti prodotti nell'interazione tra particelle cariche (protoni e ioni pesanti come C, He e O) e tessuti biologici alle energie di 200-400 MeV/u. Questi dati saranno essenziali sia per il miglioramento dei trattamenti di adroterapia, sia per lo studio e l'ottimizzazione di meccanismi di radioprotezione per gli astronauti in orbita. L'apparato di FOOT consiste in un sistema di tracking in campo magnetico ad alta precisione ed utilizzando l'approccio di cinematica inversa, permette il calcolo della sezione d'urto differenziale di frammentazione nucleare con un'incertezza minore del 5%. La ricostruzione delle tracce si basa sul software SHOE (Software for Hadrontherapy Optimization Experiment), che utilizza il toolkit GENFIT ed il suo algoritmo Kalman di ricostruzione. Questa tesi si occupa dello studio di metodi per l'ottimizzazione della ricostruzione delle tracce, focalizzandosi in particolare sul filtro di Kalman e la sua performance nell'esperimento FOOT

Radiation health research, 1986 - 1990

A collection of 225 abstracts of radiation research sponsored by NASA during the period 1986 through 1990 is reported. Each abstract was categorized within one of four discipline areas: physics, biology, risk assessment, and microgravity. Topic areas within each discipline were assigned as follows: Physics - atomic physics, nuclear science, space radiation, radiation transport and shielding, and instrumentation; Biology - molecular biology, cellular radiation biology, tissue, organs and organisms, radioprotectants, and plants; Risk assessment - radiation health and epidemiology, space flight radiation health physics, inter- and intraspecies extrapolation, and radiation limits and standards; and Microgravity. When applicable subareas were assigned for selected topic areas. Keywords and author indices are provided

csi and csi7 current source inverters for modular transformerless pv inverters

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Determining the difference between measured and calculated dose to canine oral mucosa during stereotactic radiation therapy using gafchromic™ film

2011 Fall.Includes bibliographical references.Among the therapeutic approaches available to manage canine nasal tumors, radiation therapy is considered the standard of care for achieving improved quality of life and overall survival time for these patients. Long-term local tumor control remains the goal for many radiation therapy protocols applied to patients with canine nasal tumors. Stereotactic radiation therapy (SRT), utilized by Colorado State University Animal Cancer Center (CSU-ACC), delivers maximum dose to the tumor volume, while preferentially sparing the surrounding normal structures. When treating dogs with nasal SRT, there is uncertainty with regard to the actual dose delivered to the oral mucosa due to the anatomical proximity of the tumor and the inherent error of most algorithms in calculating doses at air-tissue interfaces. A canine head phantom, dogs with spontaneously-occurring tumors, and the Gafchromic EBT film analysis system were utilized to measure radiation dose. Further comparison between measured film dose and dose calculated by the Varian Eclipse inverse planning algorithm was conducted. The results from this study demonstrate the high variability of the Analytical Anisotropic Algorithm (AAA) in calculating doses for this particular geometry. The high degree of variability results in uncertainty with regard to the prediction of delivered dose. The differences between measured and calculated doses in both the phantom (mean difference of 104 cGy per fraction, p-value of <0.0001) and the dogs (mean difference of 74 cGy per fraction, p-value of 4.2 x 10-5), suggest that the AAA underestimates the dose delivered to oral mucosa of dogs treated with SRT to manage their nasal tumors. Based upon a dose prescription of 10 Gy tumor dose per fraction in this population of dogs, an oral mucosa dose range of 3.5-6.5 Gy per fraction was measured in 88% of the cases, this range might be considered by clinicians in an effort to estimate the dose delivered to the oral mucosa while treating canine nasal tumors with SRT

Retinoblastoma

Retinoblastoma constitutes a global disease that burdens many families all over the world. This book highlights the essential basic information needed by every ophthalmologist and covers all aspects of this tumor: history, genetics, epidemiology, clinical features, diagnosis, imaging, management, and prognosis. The book includes basic knowledge, but is also designed to discuss current treatment modalities showing improved survival compared to the past. A whole chapter is dedicated to histopathological features and the American Joint Commission on Cancer staging system, with the aim of having it internationally used in all countries to improve outcomes and for research purposes. Readers will find the book enjoyable, comprehensive, and easy to understand

Eye tracking based navigation for proton beam therapy

Cancers of the eye, so-called ocular tumors, are a severe disease that may lead to blindness or even death if left untreated. A possibility to remove the tumor from the body of the patient is a so-called enucleation surgery, the removal of the eye. However, it is a drastic action and oncologists usually try to avoid it. Another treatment option is the therapy with protons. The actual proton therapy to treat ocular tumors is very successful and non-invasive. However, the navigation method that is applied for this kind of therapy requires a pre-treatment surgery, where radio-opaque clips are sutured onto the affected eyeball. These clips are used during the actual treatment to align the diseased eye with two orthogonal X-ray units. Hence, the overall treatment is invasive. The work at hand presents an alternative, completely non-invasive navigation method based on eye tracking technology. We present a new treatment scheme with a first eye tracking prototype integrated into the treatment facility at Paul Scherrer Institute (PSI). This system together with a patient specific eye model enables the medical physicist to align the patient’s eye such that the tumor gets accurately treated by the proton beam. Further, we present a second, improved eye tracking system. This time, we propose a stereo eye tracker, which only uses one physical camera to save physical space. We combine a stereo eye tracking algorithm with a clever arrangement of two planar mirrors and a single camera to get high accuracy, precision, and a compact design altogether. Finally, we present a method to quantitatively evaluate the proposed navigation system. Verifying the accuracy of the location estimate of a volunteer’s eye center is not easily possible. This is because the eye center is an intangible point, that does not correspond to an anatomical structure. Our evaluation method is based on an eye phantom on microstages and a corresponding kinematic model. Our research and development may lead to an ocular tumor treatment which will be safer, more cost-effective, and more accessible to patients suffering from this serious disease