Abstract:
The current study carried out in Radiation and Isotopes Center in Khartoum to assess 60Co-teletherapy unit performance, in which they the front pointer, graphic paper, Pin, non screen film and check plate were used to obtain the measurements.
The results reveal that there is a difference between the theoretical FS and the measured one in relation to the change of SSD; and the average difference was 1.1 cm
Also from the correlation between the QC field size (practical measurement) and inverse square low (theoretical) field size which is given by using Myneord Factor, there is 0.4 cm as excess value in practical measurement relative to theoretical method.
Also there were shift in the collimator, couch and gantry angel isocenter versus variability in SSD, angel of diaphragm rotation respectively which was ±1.1, ±1.3, 0.003 cm respectively. Also the study reveal that the scale meter SSD has a shift of 0.8 cm greater than the actual measured one and determined by front pointer. Moreover the scanning of the exposed film revealed that the penumbra profile was 2 cm and the laser beams incongruence at the isocenter was 1.1 cm.
