Suitability of Chambers in Relative Dose Measurement of Small Fields for Accelerated Photon Delivered by a Medical Linear Accelerator

Document Type : Original Paper


1 Department of Physics, University of Chittagong, Bangladesh

2 Department of Radiology, North East Cancer Hospital, Sylhet., Bangladesh

3 SSDL, Bangladesh Atomic Energy Commission, Savar, Bangladesh

4 Department of Physics, Comilla University, Cumilla


Introduction: Using the small field in modern radiotherapy, the present study aimed at measuring the relative dosimetry (scattering factor, percentage depth dose (PDD), and profile of penumbra) with ionization (FC65-G, CC13, CC01) and diode (razor) chambers.
 Material and Methods: Applying TRS-398 in Varian Clinac™ IX-5982 for 6 MV photon beams, the conditions (pressure, temperature, direction, polarity) were kept the same for a set of field sizes (1 × 1, 2 × 2, 3 × 3, 4 × 4, 5 × 5, 7 × 7, and 10 × 10 cm2), and relative dosimetry was performed at the North-East Cancer Hospital, Sylhet, Bangladesh.
Results: During the output factor measurement in small fields, the razor showed better results than CC13. Taking CC01 as a standard in small fields, the data obtained from the study showed a good agreement with those of the previously published works.
Conclusion: Razor, with extremely small active volume, was very much suited for small field dosimetry, except for PDDs.


Main Subjects


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Volume 18, Issue 4
July and August 2021
Pages 293-299
  • Receive Date: 30 January 2020
  • Revise Date: 06 May 2020
  • Accept Date: 18 May 2020
  • First Publish Date: 01 July 2021