%0 Journal Article
%T Instrumental Quality Control of Therapeutic Linear Accelerator Performance
%J American Journal Of Physics And Applications
%@ 2330-4308
%D 2017
%X The objective of the article was to assess therapeutic linear accelerator performance. Material & method used were quality control tools, direct measurement & theoretical calculation methods. The analysis of results showed that: shift of machine isocenter was 1 mm then increases up to 2 mm through the gantry angles 0 to 300กใ and 300 to 360 respectively. The diaphragm rotation isocenter clock & anti-clock wise was 1mm. the light and radiation fields showed concise matching up to 9กม9 cm, then for 10กม10, 14กม14 and 16กม16 cm there were incongruence by 0.25, 0.3 and 0.41 cm respectively. The increment of the field sizes (2กม2, 4กม4 - 20กม20) cm following SSD increment fitted with the inverse square law significantly (R 2 = 1). The theoretical (calculation method) field size was greater than the measured (practical) field size relative to SSD by 0.2 cm. The system output in Gy/Mu increases significantly (R 2 = 0.9) as the field size increases in logarithmic equation; while it decreases as SSD increases. The measured output on phantom surface was greater (0.8Gy/MU) than that calculated theoretically which was (0.5 Gy/MU). A significant (R 2 = 0.8) reduction in output reading following the increment of temperature for Linac 10 MV and 6 MV respectively, while the pressure lead to significant (0.6) increment of system output reading. TLD showed narrow penumbra extension as 0.32 and 0.2 cm for lianc 6MV and 10MV respectively compared with 0.5 and 0.3 cm at maximum depth dose when obtained from dose histogram.
%K Linear Accelerator
%K Accuracy
%K Quality Control
%K Radiotherapy
%K Instrumental
%U http://www.sciencepublishinggroup.com/journal/paperinfo?journalid=622&doi=10.11648/j.ajpa.20170505.12