Abstract:
This study was intended to assess the radiation dose output versus angle
differential in Co-60 teletherapy .the radiation output was measured at
RICK from cobalt 60 machine by used an ionization chamber and set
different SSDs, field sizesand the angleθ, the dose was decreases with
angle increase represented by this equations:
Y=1.698x+236.5 , Y=-9.337x+294.2
Y=-10.06x+284.3 , Y=-9.996x+260.5
Y=-8.76x+210.8
The data was collected shows the dose increases following the field size
increment anddose has been decreases following the SSD increment.
The correlation between field size in cm and dose in mGy with angle
factor are fitted in the following equation:y= 63.6 − 32.5 , where x
refers to field size and y refers to dose in mGy.