Dose Measurements in the Build-Up Region for the Photon Beams from Clinac-1800 Dual Energy Medical Linear Accelerator

2000 ◽  
Vol 176 (5) ◽  
pp. 223-228 ◽  
Author(s):  
Manickam Ravikumar ◽  
Ramamoorthy Ravichandran
2017 ◽  
Vol 3 (2) ◽  
pp. 287-290
Author(s):  
Michael Schaks ◽  
Johannes Zähle ◽  
Martin Janich ◽  
Patrick Hübsch ◽  
Nico Homonnay ◽  
...  

AbstractAn Elekta Synergy LINAC was used to investigate the beam quality index Q and the beam quality correction factor kQ, which is used for absolute dosimetry, in off-axis photon fields. It was found that the beam quality index Q of the photon energies with flattening filter decreases with increasing distance to the central axis, at 6 MV by 4.27% and at 15 MV by 3.98% inside a range of 15 cm off-axis. The beam quality index for flattening filter free photon fields also decreases with increasing distance to the central axis. In this case Q changed only by 1.01% inside the above range.


We focus on the comparative study of dosimetry protocols in radiotherapy for accelerated photon and electron delivered from medical linear accelerator (LINAC). In this study, a comparison between the protocols (TRS 398, DIN 6800-2 and TG 51) for both the electron and photon delivered from Clinac 2300CD and Clinac DHX 3186 were performed. We used photon beams with energies of 6 and 15 MV and electron beams of 4, 6, 9, 12, 15 and 18 MeV for both Medical Linac. In case of Clinac the maximum deviations for the relative dose at Dmax for the photon beam (15 MV) among the protocols was observed to be 1.18% between TRS-398 and TG-51, 1.56% between TG-51 and DIN 6800-2; and 0.41% between TRS-398 and DIN 6800-2. Conversely, these deviations were 3.67% between TRS-398 and TG-51, 3.92% between TG-51 and DIN 6800-2 for 4 MeV and 0.95% between TRS-398 and DIN 6800-2 in the case of Clinac 2300 CD for the PTW Markus and Exradin A10. For the measurement of the maximum absorbed dose depth to water using three protocols, the maximum deviations were observed between TRS 398 and TG-51 as well as TG51 and DIN 6800-2.


1988 ◽  
Vol 15 (2) ◽  
pp. 250-257 ◽  
Author(s):  
M. S. A. L. Al-Ghazi ◽  
B. Arjune ◽  
J. A. Fiedler ◽  
P. D. Sharma

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
K. Abdul Haneefa ◽  
T. Siji Cyriac ◽  
M. M. Musthafa ◽  
R. Ganapathi Raman ◽  
V. T. Hridya ◽  
...  

General purpose Monte Carlo code for simulation of particle transport is used to study the basic dosimetric parameters like percentage depth dose and dose profiles and compared with the experimental measurements from commercial dual energy medical linear accelerator. Varian Clinac iX medical linear accelerator with dual energy photon beams (6 and 15 MV) is simulated using FLUKA. FLAIR is used to visualize and edit the geometry. Experimental measurements are taken for 100 cm source-to-surface (SSD) in 50 × 50 × 50 cm3 PTW water phantom using 0.12 cc cylindrical ionization chamber. Percentage depth dose for standard square field sizes and dose profiles for various depths are studied in detail. The analysis was carried out using ROOT (a DATA analysis frame work developed at CERN) system. Simulation result shows good agreement in percentage depth dose and beam profiles with the experimental measurements for Varian Clinac iX dual energy medical linear accelerator.


2008 ◽  
Vol 35 (10) ◽  
pp. 4396-4403 ◽  
Author(s):  
Michalis Mazonakis ◽  
Fotini Zacharopoulou ◽  
Haralambos Varveris ◽  
John Damilakis

Author(s):  
Motiur Rahman ◽  
M Shamsuzzaman ◽  
Manoshi Sarker ◽  
Abdul Jobber ◽  
Mohsin Mia ◽  
...  

In radiotherapy treatment planning process, quality assessment (QA) is indispensable for achieving accuracy and avoidance of treatment errors. In this perspective, present study focused on the Photon and Electron beams characterization of a medical linear accelerator (LINAC) to ascertain dosimetric QA in Absolute and Reference dosimetry. In this connection, the beam outputs were investigated in terms of Dmax and Dw,max (dose at depth dmax) in absolute dosimetry for Photon and Electron beams, respectively. In accordance with the measured Dmax and Dw,max parameters, Photon and Electron beam outputs were standardized to ensure standard output of 1 cGy/MU. In reference dosimetry, the parametric evaluation was performed for dosimetric QA in terms of percent depth dose (PDD), beam profile flatness and symmetry, output factors: Scp, Sc, Sp with varying field size (FS) ranging from 4´4 cm2 to 40´40 cm2 normalized at FS 10´10 cm2 for the 6 MV and 10 MV Photon beams. The measured PDDs at 10 cm depth (D10) were found to be 66.8% and 73.6% for 6 MV and 10 MV Photon beams, respectively, with significantly small deviation of 1% and 0.8% in comparison with an international PDD protocol of British Journal of Radiology-25 (BJR -25). In the case of Electron beams characterization, PDD was verified with 10´10 cm2 cone/applicator, beam profile flatness and symmetry were analyzed at the field sizes ranging from 6´6 cm2 to 25´25 cm2 normalized at 10´10 cm2 cone/applicator, and Electron cone ratios were investigated for a given cone/applicator relative to the 15´15 cm2 one for the 6, 9, 12, 15 MeV Electron energies. The PDDs of all the Electron beams revealed reasonable consistency with manufacturer’s estimations of 90%, 80%, and 50% PDDs at various depths of ionization.


1995 ◽  
Vol 20 (1) ◽  
pp. 55-66 ◽  
Author(s):  
Anil K. Sharma ◽  
Sanjay S. Supe ◽  
N. Anantha ◽  
K. Subbarangaiah

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