Scattered Radiation from Beam Modifiers Used with Megavoltage Therapy Units

Radiology ◽  
1979 ◽  
Vol 130 (1) ◽  
pp. 233-236 ◽  
Author(s):  
J. Scrimger ◽  
Z. Kolitsi
2019 ◽  
Vol 67 (3) ◽  
pp. 190-196
Author(s):  
Ning Han

Based on a prediction method of the scattered sound pressure, an active control system was proposed in previous work for the three-dimension scattered radiation, where all the relevant simulations and experiments were implemented in three-dimensional free sound field. However, for practical applications, such as the anti-eavesdropping system or the stealth system for submarines, the sound field conditions are usually complex, and the most common case is the one with reflecting surface. It is questionable whether the previous control system is still effective in non-free sound field, or what improvements should be operated to ensure the control effect. In this article, based on the mirror image principle, two methods of calculating the control source strengths are proposed for the scattered radiation control, and numerical simulations with one-channel and multi-channel system are implemented to detect the corresponding control effect. It is seen that the local active control for the scattered radiation is still effective, and the reduction of the sound pressure level as well as the control area is extended with the increasement of the error sensors and control sources.


2009 ◽  
Vol 203 (1-6) ◽  
pp. 237-239 ◽  
Author(s):  
Sten Rasmussen ◽  
Martin Døssing ◽  
Sven Walbom-Jørgensen

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Tarik Emre Sener ◽  
Beste Melek Atasoy ◽  
Ozge Cevik ◽  
Ozlem Tugce Cilingir Kaya ◽  
Sule Cetinel ◽  
...  

AbstractObjectivesTo investigate the possible protective effects of resveratrol against oxidative testicular damage due to scattered radiation during pelvic ionizing radiation exposure in rats.MethodsRats were divided into 5 groups; control, radiation, and radiation + resveratrol therapy in early and late periods. Under anesthesia, 20 Gy ionizing radiation was applied to prostatic region. Resveratrol was administered (10 mg/kg/day) orally before ionizing radiation exposure. Animals were decapitated at the end of 1st and 10th weeks. Biochemical markers of oxidative stress; caspase-3 and sirtuin-1 protein expressions; testosterone levels were evaluated, histological examinations were performed.ResultsSignificant increases in malondialdehyde, 8-hydroxy-deoxyguanosine levels, myeloperoxidase, and caspase-3 activities were observed after ionizing radiation exposure, also superoxide dismutase and glutathione activities were significantly decreased. Radiotherapy increased caspase-3 and decreased sirtuin-1 protein expressions. Resveratrol treatment significantly reversed these parameters and also reversed the decrease in testosterone levels back to control levels in late period.ConclusionResveratrol showed antioxidant and sirtuin-activating properties against oxidative damage caused by scattered radiation to testis and provided hormonal protection. These results suggest that resveratrol may be an alternative protective agent on testicular tissues against the effects of scattered pelvic radiation.


Radiology ◽  
1963 ◽  
Vol 80 (4) ◽  
pp. 663-667 ◽  
Author(s):  
K. H. Reiss
Keyword(s):  

2016 ◽  
Vol 36 (3) ◽  
pp. 629-640 ◽  
Author(s):  
Ki Hyuk Sung ◽  
Young-Jun Jung ◽  
Soon-Sun Kwon ◽  
Gye Wang Lee ◽  
Chin Youb Chung ◽  
...  
Keyword(s):  

1996 ◽  
Author(s):  
Christiaan M. Fivez ◽  
Patrick Wambacq ◽  
Paul Suetens ◽  
Emile P. Schoeters

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