Iranian Journal of Medical Physics

Iranian Journal of Medical Physics

Applicator Attenuation Effect on Dose Calculations of Esophageal High-Dose Rate Brachytherapy Using EDR2 Film

Document Type : Original Paper

Authors
Seyed Mohsen Hosseini Daghigh 1
Seied Rabi Mahdavi 2
Seyed Mahmoud Aghamiri 1
Ramin Jaberi 3
Hamid Reza Baghani 1
Ramezan Eidi 1
Elham Boroghani 4
1 Radiation Medicine Department, Shahid Beheshti University, Tehran, Iran
2 Medical Physics Department, Tehran University of Medical Science, Tehran, Iran
3 Imam Khomeini Hospital, Tehran University of Medical Science, Tehran, Iran
4 Physics Department, Gilan University, Rasht, Iran
10.22038/ijmp.2012.326
Abstract
Introduction
Interaluminal brachytherapy is one of the important methods of esophageal cancer treatment. The effect of applicator attenuation is not considered in dose calculation method released by AAPM-TG43. In this study, the effect of High-Dose Rate (HDR) brachytherapy esophageal applicator on dose distribution was surveyed in HDR brachytherapy.
Materials and Methods
A cylindrical PMMA phantom was built in order to be inserted by various sizes of esophageal applicators. EDR2 films were placed at 33 mm from Ir-192 source and irradiated with 1.5 Gy after planning using treatment planning system for all applicators.
Results
The results of film dosimetry in reference point for 6, 8, 10, and 20 mm applicators were 1.54, 1.53, 1.48, and 1.50 Gy, respectively. The difference between practical and treatment planning system results was 0.023 Gy (<2.7%), on average.
Conclusion
Due to the similar practical results for different esophageal applicators, it can be concluded that attenuation properties of applicator wall doesn't have a significant difference with water and therefore the Flexiplan treatment planning system accuracy is further confirmed.
Keywords
Brachytherapy
Film Dosimetry
PMMA
Subjects
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Iranian Journal of Medical Physics
Volume 9, Issue 1 - Serial Number 1
March and April 2012
Pages 19-24

  • Receive Date 27 August 2011
  • Revise Date 03 March 2013
  • Accept Date 11 January 2011