scholarly journals ELECTRON ACCELERATOR FOR RADIATION THERAPY : HISTORY, PRINCIPLES AND TECHNICAL REQUIREMENTS (39th Annual Meeting)

1984 ◽  
Vol 40 (1) ◽  
pp. 34-47
Author(s):  
KEN MATSUMOTO
2021 ◽  
pp. 56-59
Author(s):  
Irina M. Lebedenko ◽  
Sergej S. Khromov ◽  
Taras V. Bondarenko ◽  
Evgenij M. Chertenkov

Considered the issues of X-ray dose control during diagnostic and therapeutic procedures using imaging tools. The dose of X-ray radiation from the visualization devices absorbed by the biological tissue of a person was determined when monitoring the position of the patient on the therapeutic table of the electron accelerator before the radiation therapy session. The processes of transmission of photons and electrons through the medium were simulated, and the X-ray spectra were measured. The emission spectrum of the Varian G-242 Rotating Anode X-ray Tube was obtained using an XR-100-CdTe spectrometer. The absorbed dose is calculated by the Monte Carlo method. The absorbed dose in the water phantom at tube voltage up to 80 kV was 0,9–1,5 mGy.


2014 ◽  
Vol 27 ◽  
pp. 1460125 ◽  
Author(s):  
P. ADRICH ◽  
A. BACZEWSKI ◽  
M. BARAN ◽  
W. DRABIK ◽  
K. GRYN ◽  
...  

A demonstrator of a new, highly mobile, robotized linear electron accelerator for Intra Operative Electron Radiation Therapy (IOERT) is under construction at National Centre for Nuclear Studies. In an IOERT treatment, a high dose of electron radiation is delivered in a single fraction directly to an exposed location after tumor ablation during oncological surgery. Due to the fact that the tumor can be located anywhere in the body, a high maneuverability of the accelerator and its adaptability to anatomical conditions are required. Moreover, since the treatment is usually executed in an unshielded operation room, the radiation protection issues are of principal importance. To assure safety of the patient and medical personnel, the therapeutic head is designed to constrain the radiation to the volume of the tumor lodge while minimizing leakage and stray radiation. For these reasons, construction of accelerators for IOERT differs considerably from the construction of linear electron accelerators for external beam radiation therapy. This paper presents some challenges and solutions in construction of the accelerator and in particular its therapeutic head with beam forming system.


2021 ◽  
Vol 10 (2) ◽  
pp. 40-49
Author(s):  
G.A. Demyashkin ◽  
◽  

Introduction. Today, a primary concern of humanity is male infertility. Recent figures suggest that the disease affects 186 million people worldwide, and its prevalence increases as men get older. In literature the radiation therapy effect on the male reproductive system is debated. Over the past decade, scientific and technological progress has definitely accelerated the development of the radiation therapy methods, and as new devices have emerged, there is a need to carefully select new dosing regimens. The aim of the experimental study was to evaluate morphological spermatogenesis indicators after targeted irradiation with electrons of variable doses. Materials and methods. Wistar rats (n=70) were once subjected to targeted ionizing irradiation on a pulsed electron accelerator NOVAC 11 with doses of 2 Gy, 4 Gy, 6 Gy, 8 Gy, 10 Gy, and 12 Gy, and a week later spermatogenesis was assessed with light microscopy. Results. In the experimental groups, we revealed a decrease in the number of germ cells; signs of degenera-tive changes and lysis of spermatids and spermatozoa; the appearance of intense pyknotic nuclei in primary spermatocytes; and a sharp decrease in the number of spermatogonia and Sertoli and Leydig cells without change in their structure. In the irradiation groups of 8–12 Gy, there was the deepest damage to the tubules, up to spermatogenic epithelium aplasia, and extensive vacuolization. Conclusion. In the testes, we observed dose-dependent progressive pathological changes in tissue structure as well as a decrease in the number of spermatogonia and other germ cells on day 7 after irradiation with a pulsed electron accelerator NOVAC 11. Keywords: electron irradiation, male infertility, spermatogenesis, seminal globs


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