Evaluation of Quality Control Program for CGR ALCYON Cobalt-60 Teletherapy Machine

Abstract

For 60Co machine, Quality Control (QC) may be defined as a program that periodically tests the physical parameters that affect the performance of machine and compares the results of such tests with some defined standards. The importance of quality control program lies in the detection any minor changes in the equipment and have corrections made before these changes become significant enough to affect the quality of treatment or causing unnecessary radiation exposure to patients or staff. The theoretical part of this study include historical background on the use of co-60 machine in radiotherapy, the construction of such machines as well as details of QC tests. The practical part includes performance of QC test on a cobalt machine at radiation & isotopes centre (RICK) in Khartoum state as well as preparation and distribution of a questionnaire on this issue to gather more information about the qc program at RICK. The performed QC tests were lamp indicator, door interlock, emergency off, table motion, audiovisual monitor, wedges, shield and shield tray, cross hair centering, gantry rotation, treatment stop timer, field size indicator and output consistency . According to the obtained results it was clear that the tested machine suffers from a lot of problems both mechanical such as wedge, shield blocks, shield tray and field size accuracy. The output of the machine was found to be very low that made the treatment time to be excessively long. At the end of this study some recommendations have been mentioned so as to improve the situation regarding the use of this equipment in radiation treatment.