Radiotherapy. stages of planning of the radiotherapy process. TNM classification

В лъчелечението днес се използват две основни групи йонизиращи лъчения - фотони и заредени частици. Фотони са рентгеновите, гама и високоенергийното спирачно лъчение (Х-лъчите), a частици - бета-лъчите, ускорените електрони, протоните, пи-мезоните и тежките йони. До скоро рентгеновата и телегаматерапията бяха водещи в България. С въвеждане на линейните ускорители най-широко е приложението на Х-лъчите и ускорените електрони. Рентгеновата терапия се прилага при кожни лезии с малки размери.Процесът на планиране на лъчелечението е труден, съдържа много стъпки и високорискови дейности, тъй като включва използването на много източници на информация и взаимодействието на различни специалисти, участващи в лъчелечебния процес. TNM класификацията се използва за определяне индикациите за лъчелечение.При всички болни, които се облъчват с линейни ускорители, се прилага триизмерно планиране. Основното е, че облъчваният обем и критичните органи се задават в поредица от срезове с дебелина, по-голяма от 0,5 см. По този начин значително се повишава точността и качеството на планираното лъчелечение. Техниките на облъчване, прилагани с линеен ускорител, са изоцентрични и налагат маркиране на изоентъра на кожата на пациента или на имобилизиращите устройства. Изоцентърът се поставя при първото облъчване на терапевтичния апарат в присъствието на лекар и физик-дозиметрист, изготвил индивидуалния план.Ако всеки лъчетерапевтичен център разполага с пълен набор от лъчетерапевтична апаратура, това дава възможност за адекватно и съвременно облъчване на всички локализации на злокачествени и доброкачествени новообразувания, с индикации за лъчелечение. В онкологичната информационна система се съхраняват: личните данни на пациента, клиничната информация относно заболяването и вида лечение, дозиметричният план на облъчването, както и подробна информация за проведеното лъчелечение. Информацията се архивира с възможност за справка на броя на извършените сеанси и облъчвани обеми, както и статистически анализ на множество данни, отнасящи се до цялостния лъчетерапевтичен процес.In modern radiotherapy two main groups of ionizing radiation are used - photons and charged particles. The photons consist of orthovoltage x-rays, gamma rays and high-energy x-rays, and the particles are beta-rays, accelerated electrons, protons, pi mesons and heavy ions. Until recently orthovoltage and telegamatherapy have been the main types of radiotherapy in Bulgaria. Now with the installation of linear accelerators, x-rays, and accelerated electrons are most commonly used. Orthovoltage radiotherapy is used for small skin lesions.The planning process of radiotherapy is difficult and contains many steps and high-risk activities as it includes the use of many sources of information and the collaboration of different specialists participating in the radiotherapy process. TNM classification is used to define the indication for radiotherapy. Three-dimensional planning is applied to all patients that are treated at a linear accelerator. The main issue here is that the target volume and the critical organs are defined as a series of consecutive CT scans with thickness of less than 0.5 cm. Thus, the accuracy and the quality of the planned radiotherapy are significantly improved. Isocenter irradiation techniqes are used with linear accelerators and this requires marking the isocenter on the patient`s skin or on the immobilization devices.The isocenter is marked during the first irradiation at the treatment machine in the presence of a physician and a physicist-dosimetrist who has developed the individual plan.If a single radiotherapy department is equiped with the full set of radiotherapy machines, this will provide adequate and modern irradiation of all malignant tumors and benign conditions requiring radiotherapy. The oncology information system stores the demographic data of the patient, the clinical information about the disease and treatment methods, the treatment as well as detailed information about the radiotherapy course . The information is archived and allows the checking of the number of performed fractions, the irradiated volumes as well as the performing of a statistical analysis of multiple data related to the entire radiotherapy process

Patient treatment path in the radiotherapy department at ST. Marina University Hospital - Varna

Лъчелечението води началото си от 1895 г., като от тогава е постигнат висок технологичен прогрес. Основната цел на лъчелечението е реализирането на предписаната лъчева доза в определен мишенен обем с едновременно минимално увреждане на съседните здрави тъкани. Резултатът е локален туморен контрол, подобрено качество на живот и удължена преживяемост.Лъчелечението в Клиниката по лъчелечение на УМБАЛ „Св. Марина` преминава през следните етапи: клинико-биологично планиране, анатомо-томографско планиране, дозиметрично планиране и изпълнение на плана на облъчване, контрол и проследяване състоянието на пациента. При консулта на пациента лекар лъчетерапевт определя целта на лъчелечението на базата на диагнозата и стадия на заболяването и назначава дата за виртуална симулация - планиращ компютърен томограф. При симулацията според подбрания протокол лъчетерапевтичният рентгенов лаборант имобилизира пациента на масата и провежда сканирането. Симулацията се включва в етапа на анатомо-томографско планиране, при което лаборантът контурира органите в риск, a лекарят дефинира клиничните мишенни обеми и предписва общата и дневната огнищни дози. На следващия етап медицинският физик изготвя индивидуален дозиметричен план, като се прилагат прецизни техники на облъчване - 3 DC, IMRT, VMAT. След като лъчетерапевтът одобри плана, физикът изготвя предварителен верификационен план, изпълняващ се от лаборанта преди първата фракция на пациента. При първото облъчване на пациента задължително присъстват лъчетерапевт, физик и рентгенов лаборант. При всяка следваща фракция рентгеновият лаборант облъчва пациента самостоятелно на линейния ускорител.При всички пациенти с цел прецизно изпълнение на плана се прилага образно насочено ЛЛ (IGRT) - верификации на позицията на пациента чрез рентгенографии, CBCT. На всички етапи медицинската радиологична сестра отговаря за манипулациите на пациента и вливанията на химиотерапевтици. По време и след терапията лечетерапевтът проследява състоянието на пациента. Тези етапи се повтарят при нужда от свръхдозиране в тумора или при бързо обратно развитие на тумора.Целта на настоящия доклад е да проследи пътя на пациента в Клиниката по лъчелечение на УМБАЛ „Св. Марина` - Варна.Since the first implementation of radiotherapy in 1896, high technology progress has been achieved in that field. The aim of radiotherapy is precise delivery of certain radiation dose in clinical target volumes with minimal damage of healthy tissues. The result is high tumor control with good quality of life and prolonged survival.The radiotherapy workflow at the Radiotherapy Department at the St. Marina University Hospital - Varna has the following specific stages: clinical and biological planning; anatomical topographic planning; treatment planning and delivering the plan, control of the symptoms and follow-up of the patients. During the consultation the radiation oncologist defines the aim of the treatment according to the cancer type and stage and an appointment for virtual simulation (planning CT) is given.During the simulation according to the selected protocol, the radiation technology technician (RTT) immobilizes the patient on the CT table and performs the CT scanning. The simulation is part of the anatomical topography planning where technicians contour organs at risk and the physician defines the target volumes and prescribes the daily and total radiation dose. At the next stage, the medical physicist per forms treatment planning, applying precise radiation techniques - 3 DC, IMRT, and VMAT. After the radiation oncologist approves the plan, the physicist prepares a preliminary verification plan running from the RTTS before the first fraction of irradiation. During the first patient irradiation a radiation oncologist, physicist and RTT are present at the linear accelerator. Then the following irradiation procedures of the patient are responsibility of RTT. In all patients to accurately implement the plan image guided radiotherapy (IGRT) is applied - verification of the position of the patient by radiographs and CBCT. At all stages a radiological nurse takes care of the patient and infuses the chemotherapeuticals. During and after treatment, the radiation oncologist follows up the patient. These stages could be repeated in case of boost or fast shrinking tumors. The aim of the present report is to demonstrate the patient treatment path at the Radiotherapy Department at the St. Marina University Hospital - Varna

Search for decays of the 9^{9}B nucleus and Hoyle state in 14^{14}N nucleus dissociation

First results of an analysis to determine contribution of decays of the unstable $^{8}$Be and $^{9}$B nuclei and the Hoyle 3$\alpha$-state to dissociation of $^{14}$N $\to$ 3He (+H) are presented. As the research material, layers of nuclear track emulsion longitudinally exposed to 2.9 $A$ GeV/$c$ $^{14}$N nuclei with at the JINR Nuclotron. Under the assumption that the He and H fragments retain momentum per nucleon of the primary nucleus, these unstable states are identified by the invariant mass calculated from the emission angles of the fragments.Comment: Article materials were presented in the report by A.A. Zaitsev at LXX International conference Nucleus - 2020, https://indico.cern.ch/event/839985/contributions/3985257 To be published in journal "Physics of Particles and Nuclei

Unstable states in dissociation of relativistic nuclei. Recent findings and prospects of researches

The invariant mass method is used to identify the $^8$Be and $^9$B nuclei and Hoyle state formed in dissociation of relativistic nuclei in a nuclear track emulsion. It is shown that to identify these extremely short-lived states in the case of the isotopes $^9$Be, $^{10}$B, $^{10}$C, $^{11}$C, $^{12}$C, and $^{16}$O, it is sufficient to determine the invariant mass as a function of the angles in pairs and triples of He and H fragments in the approximation of the conservation of momentum per nucleon of the parent nucleus. According to the criteria established in this way, the contribution of these three unstable states was evaluated in the relativistic fragmentation of the $^{28}$Si and $^{197}$Au nuclei.Comment: To be published in the European Physical Journal A. Topical issue "Light Clusters in Nuclei and Nuclear Matter: Nuclear Structure and Decay, Heavy Ion Collisions, and Astrophysics

Assessing the utility of geospatial technologies to investigate environmental change within lake systems

Over 50% of the world's population live within 3. km of rivers and lakes highlighting the on-going importance of freshwater resources to human health and societal well-being. Whilst covering c. 3.5% of the Earth's non-glaciated land mass, trends in the environmental quality of the world's standing waters (natural lakes and reservoirs) are poorly understood, at least in comparison with rivers, and so evaluation of their current condition and sensitivity to change are global priorities. Here it is argued that a geospatial approach harnessing existing global datasets, along with new generation remote sensing products, offers the basis to characterise trajectories of change in lake properties e.g., water quality, physical structure, hydrological regime and ecological behaviour. This approach furthermore provides the evidence base to understand the relative importance of climatic forcing and/or changing catchment processes, e.g. land cover and soil moisture data, which coupled with climate data provide the basis to model regional water balance and runoff estimates over time. Using examples derived primarily from the Danube Basin but also other parts of the World, we demonstrate the power of the approach and its utility to assess the sensitivity of lake systems to environmental change, and hence better manage these key resources in the future

Coupling Land Use Change Modeling with Climate Projections to Estimate Seasonal Variability in Runoff from an Urbanizing Catchment Near Cincinnati, Ohio

This research examines the impact of climate and land use change on watershed hydrology. Seasonal variability in mean streamflow discharge, 100-year flood, and 7Q10 low-flow of the East Fork Little Miami River watershed, Ohio was analyzed using simulated land cover change and climate projections for 2030. Future urban growth in the Greater Cincinnati area, Ohio, by the year 2030 was projected using cellular automata. Projected land cover was incorporated into a calibrated BASINS-HSPF model. Downscaled climate projections of seven GCMs based on the assumptions of two IPCC greenhouse gas emissions scenarios were integrated through the BASINS Climate Assessment Tool (CAT). The discrete CAT output was used to specify a seed for a Monte Carlo simulation and derive probability density functions of anticipated seasonal hydrologic responses to account for uncertainty. Sensitivity analysis was conducted for a small catchment in the watershed using the Storm Water Management Model (SWMM) developed U.S. Environmental Protection Agency. The results indicated higher probability of exceeding the 100-year flood over the fall and winter months, and a likelihood of decreasing summer low flows

A Collaborative Geospatial Shoreline Inventory Tool to Guide Coastal Development and Habitat Conservation

We are developing a geospatial inventory tool that will guide habitat conservation, restoration and coastal development and benefit several stakeholders who seek mitigation and adaptation strategies to shoreline changes resulting from erosion and sea level rise. The ESRI Geoportal Server, which is a type of web portal used to find and access geospatial information in a central repository, is customized by adding a Geoinventory tool capability that allows any shoreline related data to be searched, displayed and analyzed on a map viewer. Users will be able to select sections of the shoreline and generate statistical reports in the map viewer to allow for comparisons. The tool will also facilitate map-based discussion forums and creation of user groups to encourage citizen participation in decisions regarding shoreline stabilization and restoration, thereby promoting sustainable coastal development