Three-dimensional MRT/CT Treatment Planning for 106 Ru Eye Plaques Commissioned Using Radiochromic Film in a Solid Water Phantom

Author(s):  
B. Biritz ◽  
S. Trichter ◽  
L. Zhou ◽  
D. Nori ◽  
K. Chao ◽  
...  
2020 ◽  
Vol 8 (3) ◽  
Author(s):  
Caio Fernando Teixeira Portela ◽  
Thêssa Cristina Alonso ◽  
Arnado Prata Mourão

The precision in the dose values delivered in irradiation processes is essential for the efficiency and quality control of these processes. Radiochromic films can be used to record doses and the calibration of these films must be performed so that they can be used as dosimeters. The planning and control of the radiation released in a process allows to adjust the desired dose in the irradiated object. The photons in the primary beam interact with the matter of the object and the beam energy is attenuated due to these interactions. The attenuation depends on the characteristics of the beam and the composition of the irradiated matter. When a beam of photons propagates on an object, it tends to deposit more energy close to the surface and after reaching the maximum dose value, it decreases the dose values with depth. The films used in this work are of the Gafchromic External Beam Therapy (EBT) type, insensitive to visible light and can be prepared in places where sunlight and artificial light exists. Like many other dosimeters, which follow certain protocols, radiochromic films can provide an absolute dose measurement. Radiochromic films are characterized by their linearity, reproducibility, uniformity, sensitivity, and stability after irradiation. For the realization of the experiments, a part of the film to be irradiated was removed designated as background (BG). BG represents a piece of radiochromic film that will not change and reflects changes in film absorption in relation to environmental conditions such as temperature, visible light and scanning light, for example and that must be handled from it way that the film radiated. In this work, irradiations of a solid water phantom were performed using a source of cesium-137 with the deposition of a maximum absorbed dose value of 2.0 Gy. The phantom was placed 1,0 m far from the source collimator. Radiochromic films were placed inside the phantom to obtain the depth variation dose profile and axial dose profiles measured at 1.0 cm depth in the phantom. The dose variation profile in depth allowed to verify that the maximum dose value happened at a depth between 10 and 13 mm, very close to the surface due to the beam energy range (keV). The axial profiles presented a flatness of about 9.4 cm with a total field of 12 cm in diameter. 


2013 ◽  
Vol 54 (6) ◽  
pp. 1153-1159 ◽  
Author(s):  
M. Tanooka ◽  
H. Doi ◽  
H. Miura ◽  
H. Inoue ◽  
Y. Niwa ◽  
...  

2018 ◽  
Vol 4 (4) ◽  
pp. 045017 ◽  
Author(s):  
Samuel Trichter ◽  
Christopher G Soares ◽  
Marco Zaider ◽  
J Keith DeWyngaert ◽  
Larry A DeWerd ◽  
...  

2019 ◽  
Vol 7 (2A) ◽  
Author(s):  
Sabrina Donato Silva ◽  
André L.S Castro ◽  
Thais Melo Mendes ◽  
Luciana B. Nogueira ◽  
Tarcisio Passos Ribeiro Campos

Actually, cancer has gained a larger dimension and become a global public health problem. Radiotherapy (RT) is a neoplasia treatment and RT linear accelerators must undergo a strict dose quality control. Water or solid water phantoms can be used with this intuit. In recent years, radiochromic films with equivalent tissue composition have been widely used as dosimeters in the medical field. In this work the proposal was to analyze two distinct radiochromic film responses in water and solid water phantoms, a LINAC spectrum of 4MV beam. Solid water phantom, water phantom and EBT2 Radiochromic films were set in two distinct process of calibration. Films were exposed to a set of absorbed doses established by distinct monitor units (MU) specified in RT-center. Mathematical relations between the degree of red-intensity from digitized films and the absorbed dose for both methods were established. The coefficients of the polynomial function of the calibration curve were determined from the Origin software. The uncertainty of both processes was analyzed. The efficiency of the two calibration processes was set up. The adjustment of the calibration curve provided the coefficients of the second-order equation that relates the dose absorbed with the optical density of the film. The uncertainty regarding the calibration performed in water and solid water and the dose-error accuracy are in agreement with the literature. Both water and solid water were effective in calibration and can be used in routines of quality-control measurements. The results show that EBT2-radiochromic films are suitable to for dose-calibration in RT.


2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Ateksha Bhardwaj Khanna

Abstract Background Endodontic disease can adversely affect the quality of life and therefore early diagnosis and consequent timely treatment is of paramount importance for the Endodontist. Radiology is an essential component in treatment planning, disease monitoring and assessment of treatment outcome. Periapical radiographs and panoramic radiography are frequently utilised but they provide only two-dimensional representation of three-dimensional structures. The advent of cone beam computed tomography (CBCT) offers three-dimensional accuracy of the hard tissue images with a reasonable cost and this has revolutionised imaging of the dentomaxillofacial structures. This imaging system has been seen to overcome some limitations of conventional radiography, as brought out in this review. The improvement in the accuracy is, however, accompanied at the cost of increased radiation exposure to the patient. Nevertheless, smaller areas of exposure are normally appropriate for endodontic imaging, and adjustment in the exposure parameters can further moderate the effective dose (Loubele et al. 37(6):309-18, 2008). Aims and objectives The aim of this review is to present the pertinent literature on the various applications of cone beam computed tomography in the field of endodontics. Methods Literature was electronically searched on the following sources; Medline and Keats Library. Further, a manual search was performed on the following journals: International Endodontic Journal, Journal of Endodontics, Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, Endodontology, Journal of Dental Research, European Journal of Oral Sciences & Odontology and Dentomaxillofacial Radiology. A preliminary search was performed to gain an idea of the available literature using keywords ‘Cone Beam Computed Tomography’ to view the volume of the literature evident and identify questions to be addressed in this review. The initial search showed 243 potential articles. After scrutinising the titles and abstracts of the retrieved articles, 70 relevant studies were reviewed in full text. Furthermore, ‘published guidelines on the use of CBCT’ were also searched so as to include the results as an additional source material. All the articles eligible to be included in the review were in the English language and ranged from the year 1960 to the present. Also all the studies reviewed were based on the various uses of cone beam computed tomography in the field of endodontics. The keywords used to search were ‘Cone Beam Computed Tomography (CBCT)’, ‘Conventional radiography’, ‘Applications of CBCT in endodontics’, ‘CBCT and tooth morphology’, ‘CBCT and apical periodontitis’, ‘CBCT and vertical root fractures’, ‘CBCT and resorption’, ‘CBCT and pre-surgical assessment’, ‘CBCT and dento-alveolar trauma’ and ‘CBCT and endodontic outcome’. Results Every case is unique and CBCT should be considered only after studying each case individually. CBCT imaging needs to be adopted or used where information from conventional imaging systems is either inadequate for the management of endodontic problems or inconclusive. Having said that, it is safe to state that CBCT imaging has the potential to become the first choice for endodontic treatment planning and outcome assessment, especially when new scanners with lower radiation doses and enhanced resolution would be available.


2021 ◽  
pp. 875647932110668
Author(s):  
Amanda Hogan ◽  
Natalie Ullmer

Encephaloceles are considered neural tube defects, but their exact cause is unknown. The outcome is dismal, and essential management and counseling are needed for patients. Two-dimensional and three-dimensional sonography can be used to detect encephaloceles as early as 11 weeks, assist in treatment planning, and improve patient care. This case report presents an occipital encephalocele diagnosed by sonography and followed until delivery.


2010 ◽  
Vol 37 (7Part1) ◽  
pp. 3725-3737 ◽  
Author(s):  
Chengyu Shi ◽  
Bingqi Guo ◽  
Chih-Yao Cheng ◽  
Carlos Esquivel ◽  
Tony Eng ◽  
...  

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