Re-evaluation of the radiation safety at the teletherapy unit of the Korle Bu Radiotherapy Center, Accra, Ghana

Authors

  • Samuel Yaw Opoku Department of Radiography, School of Allied Health Sciences, University of Ghana.
  • Michael Asare-Sawiri National Center for Radiotherapy and Nuclear Medicine, Korle-Bu, Accra, Ghana.
  • Emmanuel Kwaku Nani National Center for Radiotherapy and Nuclear Medicine, Korle-Bu, Accra, Ghana.
  • Joel Yarney National Center for Radiotherapy and Nuclear Medicine, Korle-Bu, Accra, Ghana.

Keywords:

collimator, gamma radiation, cobalt, isotope

Abstract

 

Background:  The radiotherapy unit of the Korle-Bu Teaching Hospital, Accra, Ghana uses a GWGP-80 cobalt-60 teletherapy machine. On the beam-off position, leakage radiation around the radiation head must not exceed 200µSv/h at five centimetres from the surface of the radiation head or 10µSv/h at one meter from the radiation source. 

Purpose of study:  To evaluate the radiation safety at the radiotherapy center by comparing the measured scatter dose rates with standard recommendations.

Method:  Instantaneous dose rates were randomly measured in the treatment room, treatment control console room and the lobby between the treatment room and treatment control console room in both vertical and horizontal planes. Measurements of dose rates in the treatment room were taken at the beam-off position while those in the control console room and the lobby were taken at the beam-on position. The distances from a reference point to the points of measurement were also taken. The data were analysed using Microsoft Excel 2007 spread sheet.

Results:  The instantaneous dose rate in the treatment room ranged from 0.1µSv/hr -95.0µSv/hr and 0.1µSv/hr-100µSv/hr in the horizontal and vertical planes respectively. In the control console room, the range was 0.2µSv/hr in the horizontal plane and 0.1µSv/hr in the vertical plane. The range at the lobby between the treatment room and the control console room was 1.0µSv/hr in the horizontal plane and 1.5µSv/hr in the vertical plane.

Conclusion:  The scatter of gamma radiations in the treatment room (at the beam-off position), the treatment control console room and the lobby between the treatment room and the control console room (at the beam-on position) were found to be below the recommended dose rate limit.

 

Author Biographies

Michael Asare-Sawiri, National Center for Radiotherapy and Nuclear Medicine, Korle-Bu, Accra, Ghana.

Therapy Radiographer

Emmanuel Kwaku Nani, National Center for Radiotherapy and Nuclear Medicine, Korle-Bu, Accra, Ghana.

Medical Physicist

Joel Yarney, National Center for Radiotherapy and Nuclear Medicine, Korle-Bu, Accra, Ghana.

Consultant Radiation Oncologist

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Published

2012-05-25

Issue

Vol. 50 No. 1 (2012)

Section

Original Articles

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