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Cobalt radiotherapy is an external beam radiation therapy used to treat primarily bone cancer and tumors of the breast, head, and neck. Most cancer patients need radiation therapy during their curative and palliative treatment to cure or control the disease while minimizing complications to healthy tissues. In developing countries, cobalt radiotherapy machines are the most cost-effective and relevant methods of cancer treatment and cancer control. However, there is an acute shortage of radiotherapy facilities in a number of countries such as Sudan. Keeping the existing facilities functioning within the standard requirements is extremely challenging due to the shortage of spare parts, lack of quality control tools, and complications with calibrating the quality control tools, in addition to the availability of instrumentation of a low quality. The mechanical performance of two cobalt radiotherapy machines was assessed over a span of twelve months to evaluate stability, downtime, and performance. The results show the instabilities of the performance of mechanical machine parts, prolonged downtimes, and increased frequency of breakdowns of the two teletherapy machines considered in this paper. The aim was to ameliorate the availability and reliability of the equipment thus guaranteeing higher performance and reduced problems in clinical service. After the input power supply system was modified, a marked improvement in the availability of the machines was experienced. In addition, it was decided that gantry and collimator checks have to be performed routinely. Complete machine interlock tests take place daily in the morning before clinical service commences and during the day, two biomedical engineers must be in attendance as long as clinical treatment is taking place. Although these measures lead to a reduction in the number of patients treated, the improved reliability and availability of the machines make more than up for the difference

How to Cite

Zobly, S., & Reichenvater, H. . (2021). Downtime and Stability Evaluation of Mechanical Parts for Cobalt-60 Radiotherapy Units According to Standard Recommendation at NCI - U of G. Engineering & Technology Review, 2(1), 14-22. Retrieved from

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