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Wyszukujesz frazę "brachytherapy" wg kryterium: Wszystkie pola


Tytuł:
Modern Brachytherapy Techniques - Real-Time High Dose Rate Brachytherapy for Prostate Cancer
Autorzy:
Miszczak, D.
Powiązania:
https://bibliotekanauki.pl/articles/1810214.pdf
Data publikacji:
2009-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
87.53.Jw
87.55.de
87.56.-v
87.63.-d
Opis:
The "real time" technique of high dose rate brachytherapy of the prostate gland is described from the point of view of the medical physicist, as an illustration of modern radiotherapy techniques currently applied at the Centre of Oncology in Krakow. This technique, based on ultrasound imaging and on-line calculations of dose distribution around catheters inserted into the prostate volume in which a radioactive Ir-192 source is moved with the aid of an afterloading apparatus, is performed in operating-room conditions in close cooperation with the physician within stringent time limits.
Źródło:
Acta Physica Polonica A; 2009, 115, 2; 583-585
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Radiation stability of 125I-brachytherapy sources
Autorzy:
Saxena, S.
Ram, R.
Dash, A.
Joshi, P.
Venkatesh, M.
Powiązania:
https://bibliotekanauki.pl/articles/148254.pdf
Data publikacji:
2007
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
retinoblastoma
125 I-brachytherapy sources
radiation stability
SEM
leach rate
Opis:
Low energy 125I-brachytherapy sources are used for the treatment of retinoblastoma and many other forms of eye cancer. Such sources were prepared by adsorption of 125I on palladium coated silver rods and were critically evaluated for safety aspects, as per AERB standards. In order to attain low leachability and to facilitate leak free laser encapsulation of sources within titanium capsules of size 0.8 mm (f) ´ 4.75 mm (l), the radioactive source core was coated with polystyrene. With a view to study the radiation stability of such sources over a period of three weeks, both polymer coated radioactive sources and inactive source cores were separately subjected to an integrated gamma dose of ~(17.85 ´ 104) Gy (17.85 MRad), which is the dose expected to be received in three weeks from a source containing ~ 111 MBq of 125I. This was carried out to test their suitability for reuse within such period. SEM pictures of inactive source cores were taken to observe the effect of gamma radiation on palladium coating. Post-irradiation leachability and uniformity of activity of radioactive sources were evaluated and found to be satisfactory. The sources were found to be reusable safely, for repeated brachytherapy procedures over a practically useful time of at least three weeks.
Źródło:
Nukleonika; 2007, 52, 1; 13-16
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design and fabrication of 125I seeds for brachytherapy using capillary-based microfluidic technique
Autorzy:
Wang, Yuan
Zhang, Miao
Song, Tong
Chang, Zhenqi
Powiązania:
https://bibliotekanauki.pl/articles/2055673.pdf
Data publikacji:
2021
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
125I seeds
brachytherapy source
microfluidic
Monte Carlo calculation
core-shell
Opis:
A new kind of 125I seeds with a core-shell structure were synthesized by an easy assembling–disassembling coaxial capillaries microfluidic device. The dose distribution of a 125I brachytherapy source fabricated by arranging six 125I seeds collinearly within a cylindrical titanium capsule was simulated by modelling the source in a water phantom using Monte Carlo N-Particle Transport code. The infl uence of the motion and the core size of the 125I seeds on the dose distribution was also studied in this work.
Źródło:
Nukleonika; 2021, 66, 2; 55--60
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of dosimetry parameters of ADVANTAGETM 103Pd brachytherapy seed using MCNP4C computer code
Autorzy:
Ataeinia, V.
Raisali, G.
Sadeghi, M.
Powiązania:
https://bibliotekanauki.pl/articles/148136.pdf
Data publikacji:
2009
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
brachytherapy
103Pd source
dosimetry parameters
MCNP4C
ADVANTAGE TM 103Pd
Opis:
The IsoAid LLC Inc. has been introduced ADVANTAGETM 103Pd brachytherapy seed in 2006. The aim of this work is to determine the dosimetric characteristics of this seed according to AAPM’s recommendation in TG43-U1 using MCNP4C computer code. The dose rate constant has been determined to be 0.694š0.001 cGy.h–1.U–1. The radial dose function has been calculated at distances from 0.25 to 7 cm. Two-dimensional anisotropy function have been calculated at distances from 0.25 to 7 cm and at angles from 0 to 90 degrees centigrade at 10 degrees centigrade increments. The one-dimensional anisotropy function and anisotropy constant have been also calculated. The anisotropy constant in water has been calculated as 0.872š0.001. The results of this investigation are compared with the results of Meigooni et al. obtained by PTRAN code in 2006 and Sowards results obtained by PTRAN code in 2007. The comparison of the dose rate constant and the one-dimensional anisotropy function obtained from the two codes shows good agreement; also the radial dose function at distances lower than 3 cm and the two-dimensional anisotropy function at angles greater than 20 degrees centigrade are in good agreement. But, for the calculated radial dose function at distances beyond 3 cm, we observed differences between our values and Meigooni et al. and Sowards results. Also, differences between the calculated two-dimensional anisotropy function using the two codes for angles smaller than 20 degrees centigrade are considerable. The differences between the results of MCNP4C and PTRAN codes could be related to the different cross-section data libraries used in these two codes.
Źródło:
Nukleonika; 2009, 54, 3; 181-187
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of the geometry function for a brachytherapy seed, comparing MCNP results with TG-43U1 analytical approximations
Autorzy:
Raisali, G.
Ghonchehnazi, M. G.
Shokrani, P.
Sadeghi, M.
Powiązania:
https://bibliotekanauki.pl/articles/146748.pdf
Data publikacji:
2008
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
analytical approximation
brachytherapy
geometry function
MCNP
TG-43U1
Opis:
Geometry function is the only dosimetry parameter of a brachytherapy source seed, introduced in TG-43U1 protocol which is determined using calculational methods rather than physical measurement. In order to evaluate the accuracy of point and line source approximations, for calculation of the geometry function, the MCNP computer code has been used for a typical brachytherapy seed and the results have been compared. The MCNP has been used to simulate the geometry and activity distribution of a Pd-103 seed in order to calculate the geometry function for various angles and distances from the source. The comparison of results shows that at distances close to the source, the values predicted with different methods are not in agreement. The difference between the MCNP calculations and line approximation for small angles from ? = 0 to 15° is about 27% at 0.25 cm from the seed center. This difference is so much higher for point source approximation (up to a factor of 3) even up to distances of 0.5 cm from the source. As ? increases, the difference between MCNP and approximate methods is reduced. Therefore, for small distances from brachytherapy seeds, it is recommended to calculate the geometry function using more detailed methods instead of point and linear source approximations. This will provide more accurate results for other TG-43U1 dosimetry parameters such as radial dose function or anisotropy function which for some points are calculated via interpolation or extrapolation of the available discrete dosimetry data.
Źródło:
Nukleonika; 2008, 53, 2; 45-49
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zintegrowana linia radioterapeutyczna
The integrated radiotherapeutic line
Autorzy:
Miloch, W.
Wtorek, J.
Powiązania:
https://bibliotekanauki.pl/articles/268096.pdf
Data publikacji:
2009
Wydawca:
Politechnika Gdańska. Wydział Elektrotechniki i Automatyki
Tematy:
teleradioterapia
brachyterapia
akcelerator
teleradiotherapy
brachytherapy
accelerator
Opis:
Zintegrowana linia radioterapeutyczna (ZLR) stanowi złożenie sprzętu i oprogramowania służącego do precyzyjnej radioterapii. W pierwszej kolejności w referacie wyjaśniono różnice pomiędzy teleradioterapią, a brachyterapią, które stanowią podstawowe rodzaje radioterapii. Następnie przedstawiono budowę i funkcje poszczególnych części ZLR: tomografu komputerowego, systemu planowania leczenia, symulatora i akceleratora. W dalszej kolejności przedstawiono typy komputerów sterujących ich pracą. Opis ten zawiera krótką charakterystykę konfiguracji, systemu operacyjnego, sposobu zasilania i komunikacji z pozostałymi komputerami. W referacie przedstawiono także modyfikacje ZLR, które były konieczne do uzyskania zadawalającego poziomu bezpieczeństwa napromienianych pacjentów. Na zakończenie referatu poruszono problematykę rozwoju linii terapeutycznej dla części brachyterapii jak i teleradioterapii.
The Integrated Radiotherapeutic Line (IRL) constitutes composition of hardware and software for accurate radiotherapy. First, the paper explains the differences between teleradiotherapy and brachytherapy. Next, a structure of IRL is presented and functions of separate parts are described. The types of control computers are presented as well as a short technical characteristic of hardware, computer network and operating system. Another issue of the paper presents modifications of the Integrated Radiotherapeutic Line, which were necessary to achieve an appropriate level of patient’s safety. Problems arising in the course of the line integration are also presented. Finally, the paper presents issues of development of therapeutic line for brachytherapeutic part and teleradiotherapy part.
Źródło:
Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej; 2009, 26; 97-100
1425-5766
2353-1290
Pojawia się w:
Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dose enhancement in brachytherapy in the presence of gold nanoparticles : a Monte Carlo study on the size of gold nanoparticles and method of modelling
Autorzy:
Ghorbani, M.
Pakravan, D.
Bakhshabadi, M.
Meigooni, A. S.
Powiązania:
https://bibliotekanauki.pl/articles/146605.pdf
Data publikacji:
2012
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
brachytherapy
dose enhancement
gold nanoparticles
Monte Carlo (MC)
Opis:
The aim of this study was to evaluate the effect of the size of gold nanoparticles (GNPs) on dose enhancement in brachytherapy with photon emitting sources. Four photon emitting sources, 125I, 169Yb, 103Pd, and 192Ir were simulated and dose rate constant and radial dose functions were compared with published corresponding data for these sources. Dose enhancement factor in the presence of gold nanoparticles of 30 mg/ml concentration was calculated separately for nanoparticles with a diameter of 50, 100 and 200 nm. Gold nanoparticles were simulated precisely as nanospheres utilizing a lattice option in the MCNPX Monte Carlo code and the results were compared with those obtained with a simple model in which gold atoms are distributed uniformly in tumor volume as a simple mixture. Among the four mentioned sources, the dose enhancement related to 125I source is higher. Our results have shown that with gold nanoparticles of higher diameter, the level of dose enhancement is higher in the tested tumor. It has been also observed that the simple model overestimates the dose enhancement factor when compared with the precise model in which nanoparticles are defined according to the Monte Carlo code. In the energy range produced by the brachytherapy sources, the dose enhancement is higher when using brachytherapy sources with lower energy. Among the size range of gold nanoparticles used in medicine, it is predicted that nanoparticles with higher diameter can be more useful when are utilized in brachytherapy. It is also recommended that when calculating dose enhancements, a precise model be used for modelling of nanoparticles in the Monte Carlo simulations.
Źródło:
Nukleonika; 2012, 57, 3; 401-406
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development of an automation system for iodine-125 brachytherapy seed encapsulated by Nd:YAG laser welding
Autorzy:
Somessari, S. L.
Feher, A.
Sprenger, F. E.
Rostelato, M. E. C. M.
da Costa, F. E.
Calvo, W. A. P.
Powiązania:
https://bibliotekanauki.pl/articles/147664.pdf
Data publikacji:
2011
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
iodine-125 seeds
prostate cancer
brachytherapy
Nd:YAG laser welding
Opis:
The aim of this work is to develop an automation system for iodine-125 radioactive seed production by Nd:YAG laser welding, which has been used successfully in low dose rate (LDR) brachytherapy treatment. This small seed consists of a welded titanium capsule, with 0.8 mm in diameter and 4.5 mm in length, containing iodine-125 adsorbed onto a silver rod. The iodine-125 seeds are implanted into the human prostate to irradiate the tumor for cancer treatment. Nowadays, the Radiation Technology Center, at Institute for Nuclear and Energy Research, Săo Paulo, Brazil (IPEN-CNEN/SP) imports and distributes 36,000 iodine-125 seeds per year, for the clinics and hospitals in the country. However, the Brazilian market potential is now over 8,000 iodine-125 seeds per month. The local production of these iodine-125 radioactive sources became a priority for the Institute, in order to reduce the price and the problems of prostate cancer management. It will permit to spread their use to a larger number of patients in Brazil. On the other hand, the industrial automation plays an important role for iodine-125 seeds in order to increase the productivity, with high quality and assurance, avoiding human factors, implementing and operating with good manufacturing practices (GMP). The technology consists of appliance electronic and electro-mechanical parts and components to control machines and processes. The automation system technology for iodine-125 seed production developed in this work was mainly assembled employing a programmable logic controller (PLC), a stepper motor, an Nd:YAG laser welding machine and a supervisory. The statistical repeatability of correctly encapsulated sealed sources with this automation system is greater than 95 per cent.
Źródło:
Nukleonika; 2011, 56, 4; 369-374
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowanie przedoperacyjnej brachyterapii z hipertermią w leczeniu raka trzonu macicy – wstępne wyniki własne
Preoperative brachytherapy with hyperthermia in the treatment of endometrial cancer – own preliminary results
Autorzy:
Śpiewankiewicz, Beata
Piotrkowicz, Norbert
Nalewczyńska, Agnieszka
Timorek-Lemieszczuk, Agnieszka
Powiązania:
https://bibliotekanauki.pl/articles/1030788.pdf
Data publikacji:
2010
Wydawca:
Medical Communications
Tematy:
brachytherapy
combined treatment
endometrial cancer
hyperthermia
preoperative (neoadjuvant) radiotherapy
brachyterapia
hipertermia
leczenie skojarzone
radioterapia przedoperacyjna
raka trzonu macicy
Opis:
Endometrial cancer became recently the most frequently diagnosed female genital malignancy in highly developed countries. In 2003 in Poland, 3953 new cases were diagnosed (standardized coefficient: 13.00) and 783 women died thereof (standardized coefficient: 2.2). In the treatment of malignant tumors, heat has been used since Antiquity. Beneficial effect of hyperthermia relies on direct cytotoxic effect, manifesting after elevation of tissue temperature to 41-43°C. Studies performed hitherto combined hyperthermia with standard therapeutic modalities – radiotherapy and chemotherapy. The aim of this paper was to assess the effectiveness of treatment, based on determination of degree of destruction of tumor cells as assessed by histological studies, evaluation of toxicity of the treatment, assessment of quality of life one year after completion of treatment protocol and determination of 3-years’ survival rate. To date, the study encompassed 18 patients with the diagnosis of clinical stage I endometrial cancer, based on histological study of scrapings from uterine cavity and cervical canal. In 14 patients, study of material obtained at fractionated curettage of cervical canal and uterine cavity revealed endometrial cancer of the endometrioid type, in 1 – papillary type and in 3 – no histological tumor type could be determined. Surgery was performed 15-85 days (mean: 34.88 days) after completion of brachytherapy combined with hyperthermia. Based on histological study of surgical specimens, in 6 out of 18 patients (33.3%) no tumor tissue could be detected. In 2 cases (11.1%) after surgery a FIGO stage IIIC cancer was diagnosed in view of presence of metastases to inguinal lymph nodes. These patients were referred for adjuvant teleradiotherapy. In the remaining 10 cases (55.5%), FIGO stage I endometrial cancer was diagnosed. Based on the results obtained, the following conclusions were reached: 1) No complications directly associated with neoadjuvant brachytherapy with hyperthermia were noticed in any of our patients. 2) Alterations detected at surgery, purportedly associated with the treatment performed, did not compromise course or scope of surgery. 3) In 1/3 of our patients, examination of surgical specimens failed to reveal malignant tissue.
W ostatnich latach w krajach o wysokim poziomie rozwoju cywilizacyjnego rak trzonu macicy stał się najczęściej rozpoznawanym nowotworem narządów płciowych kobiety. W Polsce w 2003 roku odnotowano 3953 zachorowania na ten nowotwór (współczynnik standaryzowany – 13,00) oraz 783 zgony (współczynnik standaryzowany – 2,2). W terapii nowotworów złośliwych ciepło wykorzystuje się od dawna. Podstawą działania hipertermii jest bezpośredni efekt cytotoksyczny, ujawniający się przy podwyższeniu temperatury do 41-43°C. W przeprowadzanych dotąd badaniach hipertermię łączono ze standardowo stosowanymi metodami leczenia – radioterapią i chemioterapią. Celem pracy była ocena efektywności leczenia, dokonana na podstawie określenia stopnia uszkodzenia nowotworu w oparciu o badanie histologiczne, ocena toksyczności leczenia, ocena jakości życia po roku od zakończenia leczenia oraz ocena 3-letniego przeżycia. Dotychczas do badania włączono 18 chorych, u których rozpoznano raka trzonu macicy w I stopniu klinicznego zaawansowania na podstawie badania histologicznego wyskrobin z jamy macicy i kanału szyjki. U 14 badanych kobiet w materiale uzyskanym po frakcjonowanym wyłyżeczkowaniu kanału szyjki i jamy macicy rozpoznano raka endometrium o typie endometrioidalnym, u jednej typ brodawkowaty, zaś u 3 chorych nie określono postaci histologicznej nowotworu. Zabieg operacyjny wykonywano w odstępie od 15 do 85 dni (średnio 34,88 dnia) od zakończenia brachyterapii skojarzonej z hipertermią. Na podstawie przeprowadzonego badania histologicznego materiału pooperacyjnego u 6 z 18 pacjentek (33,3%) nie stwierdzono utkania nowotworu. W 2 przypadkach (11,1%) pooperacyjnie rozpoznano IIIC stopień klinicznego zaawansowania według FIGO, gdyż wykryto przerzuty raka do węzłów chłonnych biodrowych. Pacjentki te zostały zakwalifikowane do uzupełniającej teleradioterapii. U pozostałych 10 kobiet (55,5%) rozpoznano I stopień zaawansowania według klasyfikacji chirurgiczno-patologicznej FIGO. Na podstawie przeprowadzonych badań wysunięto następujące wstępne wnioski: 1) Bezpośrednio po przedoperacyjnej brachyterapii z hipertermią nie odnotowano u pacjentek powikłań. 2) Śródoperacyjnie obserwowane zmiany, związane z przebytym leczeniem, nie miały wpływu na przebieg zabiegu operacyjnego i jego zakres. 3) U 33,3% chorych w materiale pooperacyjnym nie stwierdzono rozrostu złośliwego.
Źródło:
Current Gynecologic Oncology; 2010, 8, 1; 21-26
2451-0750
Pojawia się w:
Current Gynecologic Oncology
Dostawca treści:
Biblioteka Nauki
Artykuł

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