RESUMEN
BACKGROUND: The Radiotherapy and Oncology Centre at Ahmadu Bello University Teaching Hospital, Zaria, Nigeria, commenced services with technical cooperation support from the International Atomic Energy Agency, Vienna, Austria in 1995. Brachytherapy services used to be offered at the ABUTH, Tudun-Wada, Zaria since 1995. Teletherapy and other Oncological services commenced at its Permanent Site, Shika- Zariaon Monday July, 2000. OBJECTIVE/METHODS: This is an incidental report of radiation over and under dose of 331 patients treated with Cobalt-60 machine (CIRUS) from July, 2000-December, 2002. RESULTS: 105 (31.7%) of the patients received 10-20% higher doses than prescribed, 161 (48.6%) received about the prescribed dose while 65 (19.7%) of the patients received under dose. CONCLUSION: The purpose of the report is to highlight that incidents and accidents can occur with the radiotherapy equipment at any centre despite trained staff operating the equipment. Any incident or accident should be reported to the appropriate national and international atomic energy agencies.