scholarly journals In vitro neoplastic transformation by neutron beams - Relative biological effectiveness and dose fractionation.

1987 ◽  
Vol 28 (4) ◽  
pp. 268-273
Author(s):  
MIEKO YASUKAWA ◽  
TOYOZO TERASIMA ◽  
TAKESHI FURUSE ◽  
HIROSHI OHARA ◽  
HIROSHI OHTSU
2019 ◽  
Vol 18 ◽  
pp. 153303381987130
Author(s):  
Francois Chevalier ◽  
Dounia Houria Hamdi ◽  
Charlotte Lepleux ◽  
Mihaela Temelie ◽  
Anaïs Nicol ◽  
...  

Chondrosarcomas are malignant tumors of the cartilage that are chemoresistant and radioresistant to X-rays. This restricts the treatment options essential to surgery. In this study, we investigated the sensitivity of chondrosarcoma to X-rays and C-ions in vitro. The sensitivity of 4 chondrosarcoma cell lines (SW1353, CH2879, OUMS27, and L835) was determined by clonogenic survival assays and cell cycle progression. In addition, biomarkers of DNA damage responses were analyzed in the SW1353 cell line. Chondrosarcoma cells showed a heterogeneous sensitivity toward irradiation. Chondrosarcoma cell lines were more sensitive to C-ions exposure compared to X-rays. Using D10 values, the relative biological effectiveness of C-ions was higher (relative biological effectiveness = 5.5) with cells resistant to X-rays (CH2879) and lower (relative biological effectiveness = 3.7) with sensitive cells (L835). C-ions induced more G2 phase blockage and micronuclei in SW1353 cells as compared to X-rays with the same doses. Persistent unrepaired DNA damage was also higher following C-ions irradiation. These results indicate that chondrosarcoma cell lines displayed a heterogeneous response to conventional radiation treatment; however, treatment with C-ions irradiation was more efficient in killing chondrosarcoma cells, compared to X-rays.


2020 ◽  
Vol 47 (8) ◽  
pp. 3691-3702 ◽  
Author(s):  
Elisabeth Mara ◽  
Monika Clausen ◽  
Suphalak Khachonkham ◽  
Simon Deycmar ◽  
Clara Pessy ◽  
...  

2012 ◽  
Vol 41 (3-4) ◽  
pp. 233-245 ◽  
Author(s):  
K.A. Higley ◽  
D.C. Kocher ◽  
A.G. Real ◽  
D.B. Chambers

Radiation weighting factors have long been employed to modify absorbed dose as part of the process of evaluating radiological impact to humans. Their use represents an acknowledgement of the fundamental difference in energy deposition patterns of charged and uncharged particles, and how this can translate into varying degrees of biological impact. Weighting factors used in human radiation protection are derived from a variety of endpoints taken from in-vitro experiments that include human and animal cell lines, as well as in-vivo experiments with animals. Nonetheless, the application of radiation weighting factors in the context of dose assessment of animals and plants is not without some controversy. Specifically, radiation protection of biota has largely focused on limiting deterministic effects, such as reduced reproductive fitness. Consequently, the application of conventional stochastic-based radiation weighting factors (when used for human protection) appears inappropriate. While based on research, radiation weighting factors represent the parsing of extensive laboratory studies on relative biological effectiveness. These studies demonstrate that the magnitude of a biological effect depends not just on dose, but also on other factors including the rate at which the dose is delivered, the type and energy of the radiation delivering the dose, and, most importantly, the endpoint under consideration. This article discusses the efforts taken to develop a logical, transparent, and defensible approach to establishing radiation weighting factors for use in assessing impact to non-human biota, and the challenges found in differentiating stochastic from deterministic impacts.


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