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

Document Type : Original Paper


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


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.
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.
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.


Main Subjects

  1. Ramezani R. Iranian annual of national cancer registration report. Tehran: Tandis; 2007. (in persian).
  2. Khan FM. The physics of radiation therapy .3th ed. Philadelphia: Lippincott Williams and Wilkins; 2003. Chapter 22, p. 521-38.
  3. Halperin E, Perez C, Brady L. Principles and Practice of Radiation Oncology. 5rd ed. Philadelphia: Lippincott Williams and Wilkins; 2005. Chapter 50, p. 1132-53.
  4. Baltas D, Sakelliou L, Zamboglou N. The Physics of Modern Brachytherapy for Oncology. Taylor & Francis; 2007.  Chapter 1, p. 8-11, Chapter 5, p. 157-63.
  5. Ash D, Gerbaulet A. The GEC ESTRO handbook of  brachytherapy. Estro; 2002. Chapter 24, p. 515-37.
  6. Rivard MJ, Coursey BM, DeWerd LA, Hanson WF, Huq MS, Ibbott GS, et al. Update of AAPM Task Group No. 43 Report: A revised AAPM protocol for brachytherapy dose calculations. Med Phys. 2004 Mar;31(3):633-74.
  7. SonoTECH. Flexiplan User's Guide and Tutorial. Version 2.5. Germany; 2009.
  8. Yang Y, Rivard MJ. Monte Carlo simulations and radiation dosimetry measurements of peripherally applied HDR 192Ir breast brachytherapy D-shaped applicators. Med Phys. 2009 Mar;36(3):809-15.
  9. Supe SS, Varatharaj C, Bijina TK, Bondel S, Sathiyan S, Ganesh KM, et al. Dosimetric evaluation of Gammamed High Dose Rate intraluminal brachytherapy applicators. Rep Pract Oncol Radiother. 2007;12(6):313-7.
  10. Lambert J, McKenzie DR, Law S, Elsey J, Suchowerska N.  A plastic scintillation dosimeter for high dose rate brachytherapy. Phys Med Biol. 2006;51(21):5505-16.