12 research outputs found

    Electronic brachytherapy for gynecological cancers — a systematic review

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    Background: The purpose of this manuscript is to provide an in-depth literature review of the management of endometrial and cervical cancers with electronic brachytherapy. Materials and methods: An extensive literature search was performed and 9 articles were selected based on preset criteria. Results: The reviewed studies provided dosimetric and clinical results. Patient populations were diverse and prescribed doses varied. When treatment plans were compared to those using cobalt 60 (60Co) and iridium 192 (192Ir) sources researchers found lower or equivalent doses in organs at risk while the doses at the applicator surface were significantly higher for electronic brachytherapy. In the eligible studies, a total of 72 patients received treatment with AxxentXoft vaginal applicator, 29 were treated with the Intrabeam vaginal applicator, and 8 with AxxentXoft cervical applicator. Conclusions: All authors found that electronic brachytherapy was safe and well tolerated as higher mucosal doses did not present as adverse clinical effects. Electronic brachytherapy for gynecological cancers has the potential to achieve equivalent tumor control while minimizing bowel and urinary toxicity thus improving the quality of life. More clinical data is needed to stratify patients who would benefit the most

    Тechnical aspects of cardiac magnetic resonance tomography

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    Кардиомагнитно-резонансната томография (КМРТ) е метод с висока диагностична стойност при оценката на сърдечната виталност чрез прилагането на различни перфузионни техники, както и при оценката и диагностицирането на ранни исхемични промени в миокарда. Целта на настоящия обзор е да се направи преглед на различните технически аспекти при КМРТ. Основен проблем при КМРТ изследванията е влошаването на качеството на образа поради наличието на двигателни артефакти. Това налага разработването на техники за ЕКГ тригериране и тригериране на дишането или техники за задържане на дишането и въвеждането им в практиката. За разлика от повечето други приложения на магнитно-резонансната томография, използваните равнини при КМРТ се определят по отношение на ориентацията на сърцето така, че да са успоредни и ортогонални на сърдечните оси. При КМРТ се използват две основни групи секвенции: 1) за определяне на морфологията, функцията и кръвотока и 2) за подсигуряване на добър тъканен контраст на сърцето. Технологичното развитие на метода не спира, като продължават да се разработват техники и секвенции за подобряване на диагностичните възможности при КМРТ. Успешно провеждане на всяко едно КМРТ изследване се постига чрез правилно планиране, цялостно разбиране на сърдечните равнини и подходящ избор на техническите параметри за съответните секвенции в зависимост от търсената клинична находка. Cardiac magnetic resonance tomography (CMRT) is a method of high diagnostic value in the assessment of cardiac vitality through the application of various perfusion techniques, as well as in the evaluation and diagnosis of early myocardial ischemic changes. The aim of this article is to review the different technical aspects of CMRT. A major problem in CMRT studies is the deterioration of image quality due to the presence of motion artefacts. This necessitates the development of ECG-gated and respiratory triggered or breath-holding techniques and their implementation in practice. In contrast to most other applications of MRT, the planes used in CMRT are defined with respect to the orientation of the heart so that they are parallel and orthogonal to the cardiac axes. Two main groups of sequences are used in CMRT: 1) to determine morphology, function, and blood flow and 2) to provide good tissue contrast of the heart. Technological development of the method has not stopped, and techniques and pulse sequences continue to be developed to improve the diagnostic capabilities of CMRT. Through proper planning, a thorough understanding of the cardiac planes, and appropriate selection of technical parameters for the respective sequences depending on the clinical finding being addressed, a successful performance of each CMRT study is achieved

    T1 and T2 mapping – basic principles and clinical application

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    Кардиомагнитно-резонансната томография (КМРТ) е широко използван метод при диагностиката на сърдечно-съдовите заболявания. През последното десетилетие бяха разработени нови техники, позволяващи получаването на количествени параметри за промените в миокарда. Т1 и Т2 картирането са част от рутинния КМРТ протокол и позволяват директно количествено определяне на Т1 и Т2 времената за релаксация в миокарда, както и изчисляването на екстрацелуларния обем. Това са важни биомаркери както за диагностиката на различните заболявания на миокарда, така и за проследяване на лечението и определяне на прогнозата. Целта на този обзор е да се направи кратък преглед на базовите принципи на техниките Т1 и Т2 картиране, както и на основните им приложения при различните видове кардиомиопатии. Cardiac magnetic resonance tomography is widely used method in the diagnosis of cardiovascular diseases. In the last decade, new techniques have been developed to obtain quantitative parameters of myocardial changes. T1 and T2 mapping are part of the routine CMRT protocol and allow direct quantification of T1 and T2 relaxation times in the myocardium as well as the calculation of extracellular volume. These are important biomarkers both for the diagnosis of various myocardial diseases and for monitoring treatment follow-up and determining prognosis. The purpose of this article is to provide a brief overview of the basic principles of the T1 and T2 mapping techniques, as well as their main applications in different types of cardiomyopathies

    T1 and T2 mapping – basic principles and clinical application

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    Кардиомагнитно-резонансната томография (КМРТ) е широко използван метод при диагностиката на сърдечно-съдовите заболявания. През последното десетилетие бяха разработени нови техники, позволяващи получаването на количествени параметри за промените в миокарда. Т1 и Т2 картирането са част от рутинния КМРТ протокол и позволяват директно количествено определяне на Т1 и Т2 времената за релаксация в миокарда, както и изчисляването на екстрацелуларния обем. Това са важни биомаркери както за диагностиката на различните заболявания на миокарда, така и за проследяване на лечението и определяне на прогнозата. Целта на този обзор е да се направи кратък преглед на базовите принципи на техниките Т1 и Т2 картиране, както и на основните им приложения при различните видове кардиомиопатии. Cardiac magnetic resonance tomography is widely used method in the diagnosis of cardiovascular diseases. In the last decade, new techniques have been developed to obtain quantitative parameters of myocardial changes. T1 and T2 mapping are part of the routine CMRT protocol and allow direct quantification of T1 and T2 relaxation times in the myocardium as well as the calculation of extracellular volume. These are important biomarkers both for the diagnosis of various myocardial diseases and for monitoring treatment follow-up and determining prognosis. The purpose of this article is to provide a brief overview of the basic principles of the T1 and T2 mapping techniques, as well as their main applications in different types of cardiomyopathies

    Role of cardiac magnetic resonance imaging in the diagnosis of nonischemic cardiomyopathies

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    През последните десетилетия кардиомагнитно-резонансната томография (КМРТ) се налага като ценен инструмент в диагностиката на пациенти със сърдечна недостатъчност или с риск от такава. Благодарение на способността си за тъканна характеристика на промените в миокарда КМРТ може да предостави подробна и клинично полезна информация относно вида и тежестта на сърдечната увреда. Методът заема важно място не само за разграничаване на исхемична от неисхемична кардиомиопатия, но и допринася за правилното диагно-стициране на подтиповете на неисхемичните кардиомиопатии. Освен това е широко приет и като референтен стандарт за количествена оценка на миокардна маса, обеми и фракция на изтласкване. Целта на тази статия е да се направи преглед на ролята на КМРТ в диагностиката и лечението на неисхемичните кардиомиопатии. In recent decades, cardiac magnetic resonance imaging (CMR) has been established  as a valuable tool in the diagnosis of patients with or at risk of heart failure. With its ability to characterize tissue changes in the myocardium, CMR can provide detailed and clinically useful information about the type and severity of cardiac damage. The method is not only important for differentiation of ischemic from non-ischemic cardiomyopathy, but also contributes to the correct diagnosis of non-ischemic cardiomyopathy subtypes. It is also widely accepted as a reference standard for the quantification of myocardial mass, volumes and ejection fraction. The purpose of this article is to review the role of CMR in the diagnosis and treatment of non-ischemic cardiomyopathies

    Multicentric survey of patient doses in fluoroscopy guided diagnostic and interventional cardiac procedures: comparison with Diagnostic Reference Levels and follow-up levels for patients at risk for radiation induced skin effects

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    Въведение. Интервенционалните кардиологични процедури, често са свързани с голямо облъчване на пациентите, поради което изискват специално внимание по отношение на защитата от появата на радиационно индуцирани ефекти при пациента.Материали и методи. Проучването на типичните стойности на дозата е проведено ретроспективно, в девет лечебни заведения, с общо четиринадесет ангиографски уредби. За две от най-често извършваните процедури - перкутанна коронарна интервенция (PCI) и коронарна артериография (CA) са изчислени типичните стойности на величините произведение керма-площ (КАП), кумулативна доза (КД) и време на скопия (ВС) и са сравнени с актуалните Национални диагностични референтни нива (НДРН) за България. Извършен е анализ на данните по отношение на риска от възникване на кожно индуцирани ефекти, вследствие на интервенционалните кардиологични процедури.Цел. 1) да се представят и анализират типичните стойности на величината КАП за най-често провежданите кардиологични процедури - перкутанна коронарна интервенция и коронарна артериография в кардиологични отделения с голяма работна натовареност и да се сравнят с НДРН; 2) да се сравнят дозите на пациентите с публикуваните в Наредба 2 нива за проследяване, за установяване на пациенти с риск за възникване на радиационно индуцирани ефекти.Резултати. Резултатите показват, че типични стойности на изследваните величини за PCI и CA при някои от уредбите, са по-високи от НДРН. Във всяко от разглежданите лечебни заведения има пациенти с поне едно превишено ниво за проследяване за процедура PCI.Изводи. Резултатите показват потенциал за оптимизиране, както на работата в отделенията с високи типични стойности на дозата, така и при уредбите с много ниски типични стойности на изследваните величини. При проследените пациенти не се наблюдават оплаквания и поява на радиационно индуциран ефект. Изготвянето и въвеждането в рутинната клинична практика на процедури за рутинно прилагане на „Инструкцията за пациента след проведена интервенционална/и процедура/и с по-голяма степен на сложност и дълго време на скопия“ ще позволи навременна диагностика и навременно лечение на кожните ефекти в следствие на проведените кардиологични процедури под рентгенов контрол. Introduction. Interventional cardiac procedures are often associated with high patient exposure and therefore require special care in protecting patients from radiation-induced effects.Materials and methods. A retrospective study of typical patients’doses was performed in nine hospitals, with a total number of fourteen angiography systems. The typical values for kerma-area product (KAP), cumulative dose (CD) and fluoroscopy time (FT) for two of the most commonly performed procedures - percutaneous coronary intervention (PCI) and coronary arteriography (CA), were calculated and compared with the Bulgarian National Diagnostic Reference Levels (NDRL). Data analysis, regarding the risk of radiation-induced skin effects due to interventional cardiac procedures, was performed.Aim. 1) to present and analyze the typical KAP values for PCI and CA procedures in cardiology departments with high workload and to compare them with the NDRL; 2) to compare the patient doses with the follow-up levels published in Ordinance 2, to identify patients at risk for radiation-induced effects.Results. The results show that typical values for PCI and CA procedures for some of the angiography systems are higher than the NDRL. In all investigated departments there are patients with at least one exceeded follow-up level for PCI.Conclusions. The results show a potential for optimization in the departments with both high or very low typical dose or FT values. No radiation-induced effect was observed in the followed-up group of patients. The introduction of procedure with "Instruction to the patient after an interventional cardiac procedure(s) with greater complexity and a long fluoroscopy time" for patient follow-up and its regular implementation into the routine clinical practice will help for timely diagnosis and treatment of radiation-induced skin effects after cardiac procedures under fluoroscopy control

    Intraoperative Radiotherapy with Balloon-Based Electronic Brachytherapy System—A Systematic Review and First Bulgarian Experience in Breast Cancer Patients

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    (1) Background: We aimed to analyze currently available studies with intraoperative radiotherapy (IORT) as a choice of treatment where the Xoft Axxent® electronic brachytherapy (eBx) system was used as a single-dose irradiation and an exclusive radiotherapy approach at the time of surgery in patients with early breast cancer (EBC). We also compared the results of the systematic review to the Bulgarian experience. (2) Methods and Materials: We performed a systematic review of the studies published before February 2021, which investigate the application of a single-fraction 20 Gy radiation treatment, delivered at the time of lumpectomy in EBC patients with the Xoft Axxent® eBx System. A systematic search in PubMed, Scopus, and ScienceDirect was performed. The results are reported following the PRISMA guidelines. The criteria on patients’ selection for IORT (the additional need for EBRT), cosmetic outcomes, and recurrence rate from the eligible studies are compared to the treatment results in Bulgarian patients. (3) Results: We searched through 1032 results to find 17 eligible studies. There are no published outcomes from randomized trials. When reported, the cosmetic outcomes in most of the studies are defined as excellent. The observed recurrence rate is low (1–5.8%). Still, the number of patients additionally referred to postoperative external breast radiotherapy (EBRT) is up to 31%. Amongst the 20 patients treated in Bulgaria, the cosmetic outcomes are also evaluated as excellent, five of which (25%) are referred for EBRT. Within median follow-up of 39 months, there was one local and one distal recurrence. (4) Conclusions: Current evidence demonstrates the Xoft Axxent® eBx system as a safe and feasible technique for IORT delivery in EBC patients. There are no randomized controlled trials conducted at this time point to prove its long-term effectiveness. Better patient selection and a reimbursement strategy have to be proposed to extend the application of this technique in Bulgaria

    Development of breast lesions models database

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    PURPOSE: We present the development and the current state of the MaXIMA Breast Lesions Models Database, which is intended to provide researchers with both segmented and mathematical computer-based breast lesion models with realistic shape. METHODS: The database contains various 3D images of breast lesions of irregular shapes, collected from routine patient examinations or dedicated scientific experiments. It also contains images of simulated tumour models. In order to extract the 3D shapes of the breast cancers from patient images, an in-house segmentation algorithm was developed for the analysis of 50 tomosynthesis sets from patients diagnosed with malignant and benign lesions. In addition, computed tomography (CT) scans of three breast mastectomy cases were added, as well as five whole-body CT scans. The segmentation algorithm includes a series of image processing operations and region-growing techniques with minimal interaction from the user, with the purpose of finding and segmenting the areas of the lesion. Mathematically modelled computational breast lesions, also stored in the database, are based on the 3D random walk approach. RESULTS: The MaXIMA Imaging Database currently contains 50 breast cancer models obtained by segmentation of 3D patient breast tomosynthesis images; 8 models obtained by segmentation of whole body and breast cadavers CT images; and 80 models based on a mathematical algorithm. Each record in the database is supported with relevant information. Two applications of the database are highlighted: inserting the lesions into computationally generated breast phantoms and an approach in generating mammography images with variously shaped breast lesion models from the database for evaluation purposes. Both cases demonstrate the implementation of multiple scenarios and of an unlimited number of cases, which can be used for further software modelling and investigation of breast imaging techniques. The created database interface is web-based, user friendly and is intended to be made freely accessible through internet after the completion of the MaXIMA project. CONCLUSIONS: The developed database will serve as an imaging data source for researchers, working on breast diagnostic imaging and on improving early breast cancer detection techniques, using existing or newly developed imaging modalities.status: publishe

    Development of breast lesions models database

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    We present the development and the current state of the MaXIMA Breast Lesions Models Database, which is intended to provide researchers with both segmented and mathematical computer-based breast lesion models with realistic shape
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