Taherkhani A, Mohammadi M, Saboori M, Changizi V. Evaluation of the physical characteristic of Cerrobend blocks used for radiation therapy. Int J Radiat Res 2010; 8 (2) :93-101
URL:
http://ijrr.com/article-1-622-en.html
, mohammadi@umsha.ac.ir
Abstract: (17021 Views)
Background: In Radiation Therapy, the sparing of
normal tissues can be performed using either
multi-leaf collimators or Cerrobend blocks. The
current work focuses on the physical characteristics
of Cerrobend blocks including attenuation coefficient,
effective penumbra width and isodose curves undulation
in penumbral regions. Materials and Methods: All
measurements were performed using a dual energy
linac and the Cerrobend blocks designed and
fabricated using a commercial Cerrobend material.
Data were collected using a calibrated ionization
chamber as well as EDR2 films. Results: The results
showed that the attenuation coefficient was found to
be 0.4475 and 0.4276 cm-1 for photon beams 6MV
and 15 MV, respectively, and a potential air bubble
with a diameter greater than 3 mm affects beam
attenuation significantly. The optimum Cerrobend
block width was found to be around 16 mm. The
isodose curves scalloping achieved for secondary
collimator jaws, were also similar. Conclusion: If
Cerrobend blocks are used as a basic method to
protect normal tissues, its physical characteristics will
be recommended to be taken into account comprehensively.
Iran. J. Radiat. Res., 2010 8 (2): 93-101
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