321 / 1245
OF: small fields
-5.0%
-4.0%
-3.0%
-2.0%
-1.0%
0.0%
1.0%
2.0%
3.0%
4.0%
5.0%
0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0
Side of equivalent square field size at isocenter (cm)
Relative difference normalized to EFD OF
Exradin W1 Cal. A
Exradin W1 Cal. B
Exradin W1 Cal. C
Pinpoint
Relative differences of OF normalized to EFD-3G OF.
OF are referred to a 10 x 10 cm
2
field size.
Parallel to beam axis
Figure 1. Calibration plate with the scintillator in the maximum fiber configuration (left) and
minimum fiber configuration (right).
Perpendicular to beam axis
The calibration methodology proposed by
the manufacturer is not appropriate for
measuring output factors for small fields.
Calibration using smaller fields and the
detector axis parallel to beam axis should
be used.
These results show that the CRL and gain
depend on field size and orientation of the
scintillator.
Organic scintillator
(W1 Standard Imaging)