Journal of Medical Physics
ORIGINAL ARTICLE
Year
: 2022  |  Volume : 47  |  Issue : 3  |  Page : 235--242

Comparison and validation of multiple detectors against monte carlo simulation for the use of small-field dosimetry


Nazia Parveen1, Prabhakar Ramachandran1, Venkatakrishnan Seshadri1, Ben Perrett1, Andrew Fielding2 
1 Therapeutic Physics, Radiation Oncology, Cancer Services, Princess Alexandra Hospital, Woolloongabba, Queensland, Australia
2 School of Chemistry and Physics, Queensland University of Technology (QUT), Brisbane, Australia

Correspondence Address:
Dr. Prabhakar Ramachandran
Cancer Services, Princess Alexandra Hospital, Woolloongabba, Queensland 4102
Australia

Aim: The aim of this study was to compare the Exradin W2 scintillator, PTW microDiamond, IBA Razor Nano, and IBA Razor chamber detectors for small-field dose measurements and validate the measured data against the EGSnrc user code and observe the variation between daisy-chained and direct measurement methods for the above detectors. Materials and Methods: The W2 scintillator, microDiamond, Razor Nano, and Razor chamber detectors were used to measure the in-plane and cross-plane profiles and the output factors (OFs) at 10 cm depth, and 90 source-to-surface distance for 6MV X-rays (Elekta Versa HD). The field sizes ranged from 0.5 cm × 0.5 cm to 5 cm × 5 cm. The BEAMnrc/DOSXYZnrc user codes (EGSnrc) were used to simulate the reference profiles. Gamma analysis was performed to compare the measured and simulated dose distributions. Results: The OFs measured with the W2 scintillator, microDiamond, Razor Nano chamber, Razor chamber, and the calculated Monte Carlo (MC) showed agreement to within 1% for the 3 cm × 3 cm field size. The uncertainty in the MC simulation was observed to be 0.4%. The percent difference in OFs measured using daisy-chained and direct measurement methods was within 0.15%, 0.4%, 1.4%, and 2.4% for microDiamond, W2 scintillator, Nano, and Razor chamber detectors, respectively. Conclusion: The lateral beam profiles and OFs of W2 scintillator, microDiamond, Razor Nano, and Razor chambers exhibit good agreement with the MC simulation within the nominal field sizes. Our results demonstrate that we can achieve considerable time-saving by directly measuring small-field OFs without daisy-chained methods using microDiamond and W2 scintillator. In terms of ease of use, sensitivity, reproducibility, and from a practical standpoint, we recommend microDiamond for small-field dosimetry.


How to cite this article:
Parveen N, Ramachandran P, Seshadri V, Perrett B, Fielding A. Comparison and validation of multiple detectors against monte carlo simulation for the use of small-field dosimetry.J Med Phys 2022;47:235-242


How to cite this URL:
Parveen N, Ramachandran P, Seshadri V, Perrett B, Fielding A. Comparison and validation of multiple detectors against monte carlo simulation for the use of small-field dosimetry. J Med Phys [serial online] 2022 [cited 2022 Dec 7 ];47:235-242
Available from: https://www.jmp.org.in/article.asp?issn=0971-6203;year=2022;volume=47;issue=3;spage=235;epage=242;aulast=Parveen;type=0