Quality assurance (QA) in all aspects of radiotherapy reduces the number of instances of
accidental dose misadministration. Reduction of such errors and uncertainties plays an
important role in the outcome of radiotherapy. As part of the audit supported by the
IAEA in Ghana this study was designed to review the whole chain of activities in 3D
conformal radiotherapy (3D-CRT) workflow, from patient data acquisition to treatment
planning and dose delivery.The study focused on dosimetry part of the treatment
planning and delivery processes.
The audit was conducted in three (3) radiotherapy centers in Ghana using CIRS
anthtropomophic thorax phantom. The phantom was scanned with a computed
tomography unit (CT). Treatment plans for seven (7) different test cases involving
various beam configurations based on TECDOC 1583 were prepared on local treatment
planning systems (TPSs) by local medical physicist. The phantom was irradiated
following the treatment plans and absorbed dose to water in specific points of the
phantom were determined using TRS 398 protocal with an ion chamber connected to an
electrometer. The percentage deviations between the measured and calculated doses in
specific measuring points were computed and compared to their corresponding
predefined agreement criteria.
37 photon beams with energies 1.25 MV and 6 MV were studied and two calculation
algorithms (Collapsed Cone and Superposition/Convolution algorithms) were
investigated. Most deviation (42%) were discoverd in the lung equivalent material. A
maximum deviations of 52.9% at centre 2 and -8.9% at centre 1 were observed for
Convolution/Superposition and Collasped Cone algorithms respectively in test case 4,
measuring point 6.
Eastern Network, L (2021). Inter-Institutional Dosimetric Comparison for Radiotherapy Centres in Ghana Using CIRS Thorax Phantom. Afribary.com: Retrieved April 15, 2021, from https://afribary.com/works/inter-institutional-dosimetric-comparison-for-radiotherapy-centres-in-ghana-using-cirs-thorax-phantom
Library, Eastern Network. "Inter-Institutional Dosimetric Comparison for Radiotherapy Centres in Ghana Using CIRS Thorax Phantom" Afribary.com. Afribary.com, 03 Apr. 2021, https://afribary.com/works/inter-institutional-dosimetric-comparison-for-radiotherapy-centres-in-ghana-using-cirs-thorax-phantom . Accessed 15 Apr. 2021.
Library, Eastern Network. "Inter-Institutional Dosimetric Comparison for Radiotherapy Centres in Ghana Using CIRS Thorax Phantom". Afribary.com, Afribary.com, 03 Apr. 2021. Web. 15 Apr. 2021. < https://afribary.com/works/inter-institutional-dosimetric-comparison-for-radiotherapy-centres-in-ghana-using-cirs-thorax-phantom >.
Library, Eastern Network. "Inter-Institutional Dosimetric Comparison for Radiotherapy Centres in Ghana Using CIRS Thorax Phantom" Afribary.com (2021). Accessed April 15, 2021. https://afribary.com/works/inter-institutional-dosimetric-comparison-for-radiotherapy-centres-in-ghana-using-cirs-thorax-phantom