FABRICATION AND CHARACTERZATION OF BEAM QUALITY PHANTOM FOR EXTERNAL BEAM RADIOTHERAPY

Document Type : Original Paper

Authors

1 Karunya University

2 Department of Physics, School of Sciences, Arts, Media and Mangement, Karunya Institute of Technology and Sciences, Coimbatore-641 114 Tamilnadu India

3 Assistant Professor and Head Department of Medical Physics

4 Medical Physics, research scholar, Dr. N.G.P college, coimbatore.

5 ASSISTANT PROFESSOR AND HEAD DEPARTMENT OF MEDICAL PHYSICS BHARATHIAR UNIVERSITY

6 Department of Medical Physics, Bharathidasan University

Abstract

Introduction: Radiation dose measurement plays a major role in Radiation Dosimetry. Effective dose delivery to the patient is ensured with the prescription of some protocol called Quality assurance (QA). It is given by beam quality factor TPR 20/10 which is one of the QA protocols. This ratio is measured by various methods using Radiation Field Analyzer (RFA), slab phantoms etc.

Materials and methods: Phantom is made of PMMA material filled with Gelatin. Ion chamber is used to measure the dose at 20 and 10 cm depth. As the reference condition is maintained, the Gel phantom is kept for irradiation in Siemens LINAC machine. Initially Source Axis Distance (SAD) of 100 cm from surface and 10 x 10 cm2 of field size. The measurement is taken at 10 and 20 cm depth in gantry angles 90° and 270° and the ratio of these values are taken and compared with the measurements of water based TPR phantom measurement ratios, also output measurement is done using the same phantom. Reference conditions are maintained, 100 cm Source Skin Distance (SSD), 10 cm depth, and 10 x 10 cm2.

Results: The values for TPR20,10 ratio for the Gelatin and water phantom is measured using the above methods and the values are tabulated and compared . Likewise the output measurements are done and tabulated for the comparison. These measurements are carried out for several days to check the repeatability, reproducibility of the phantom. Also the measured set of values analyzed using mean, median, standard deviation etc.

Conclusion: It is concluded that, the fabricated phantom had a good results in its response. And the result projects that the phantom can be a better alternative for the other phantom materials and gel has more advantages over water, we conclude that gel can be used for better dosimetric procedures.

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Articles in Press, Accepted Manuscript
Available Online from 19 October 2022
  • Receive Date: 20 July 2019
  • Revise Date: 27 September 2022
  • Accept Date: 19 October 2022