Assessment of Radiation Dose Output versus Angle Differential in Co 60 Teletherapy

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.