Abstract:
The most important criterion of patient position in radiotherapy is accuracy and precision in all
courses (fractions) of treatment to deliver prescribed treatment dose. The study was performed at
Radiation and Isotopes Center of Khartoum. During period of June 2014 to January 2015. The
aim of the study was to determine inaccurate of patient positioned using laser. The patient
Alignment and position monitoring is carried out by comparing the current laser positions of the
markers with those of an initial reference position. Professional radiotherapy technologist were
asked to reposition 50 patients carefully using traditional laser centering procedures. The results
revealed significant repositioning errors even in highly controlled conditions.
Affecting
particularly body areas relatively far from the skin reference points used for laser alignment. The
results allow the radiotherapy technicians to take suitable countermeasures in case of significant
errors (Conventional Set-up is equally (4.87+0.47 mm) for x-direction reading) ,(4.00±0.46 mm)
x , and Laser Reading (3.5 ± 0 mm). (Conventional set-up (4.38± 0.19 mm) for y ,(3.73±0.18
mm) y direction , and Laser is ( 3.75 ± 0) . conventional set-up is ( 4.83± 0.34 mm) for z-axis , (
4
3.87 ± 0.36 mm) z direction and Laser is( 3.5 ±0mm ) In addition, the use of the laser beam for
.automatic position control is envisaged
