Chest Dose Assessment in Breast Cancer Therapy Using Two Electron Energies

Document Type : Original Article (s)

Authors

1 Professor, Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran

2 Associate Professor, Department of Radiation Oncology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran

3 Department of Medical Radiation Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran

4 Department of Medical Physics-Clinical Biochemistry, School of Medicine, Golestan University of Medical Sciences, Gorgan, Iran

Abstract

Background: Electron therapy has advantages of dose uniformity in target volume and dose reduction in deeper tissues for breast cancer therapy. The aim of this study was to determine observed dose in target volume and normal tissues such as lung in breast cancer therapy after mastectomy.Methods: The phantom was designed based on the chest wall computed tomography (CT) images after mastectomy and treatment planning software. Two linear accelerator (Neptune 10 and Saturn 20) machines were used to deliver electron beams at a dose of 200 cGy (10 and 13 MeV). Dose measurements were done using thermoluminescence dosimeter lithium fluoride chips (TLD-100: LiF: Mg; Tl).Findings: The percentage of measured dose in internal mammary nodes, axillary nodes, and chest wall using 13 MeV was found to be 97.5, 96, and 98, respectively. In treatment with 10 MeV electron, this values changed to 99.7, 90.5, and 77 percent, respectively. The anterior lung percentage dose was 78 with 13 MeV electrons while the posterior part of lung received 47 percent with 10 MeV electron beam. Dose values for anterior and posterior part of lung changed to 83 and 45 percent, respectively.Conclusion: Using 13 MeV, internal mammary and axillary lymph nodes as well as the chest wall received adequate doses but lung received excessive dose. Using 10 MeV, internal mammary nodes and chest wall were well exposed to radiation, but axillary lymph nodes did not receive enough dose. Therefore, this dose shortage should be compensated by additional posterior fields using radiation therapy with photon energies.

Keywords

References

  1. Khan FM. Treatment planning in radiation oncology. 2nd ed. Philadelphia, PA: Lippincott Williams and Wilkins. 2006. p. 391-429.
  2. Hogstrom KR, Almond PR. Review of electron beam therapy physics. Phys Med Biol 2006; 51(13): R455-R489.
  3. Sharma PK, Jamema SV, Kaushik K, Budrukkar A, Jalali R, Deshpande DD, et al. Electron arc therapy for bilateral chest wall irradiation: treatment planning and dosimetric study. Clin Oncol (R Coll Radiol) 2011; 23(3): 216-22.
  4. Tenhunen M, Nyman H, Strengell S, Vaalavirta L. Linac-based isocentric electron-photon treatment of radically operated breast carcinoma with enhanced dose uniformity in the field gap area. Radiother Oncol 2009; 93(1): 80-6.
  5. Rezaee V, Shahbazi-Gahrouei D, Monadi S, Saeb M. Evaluation of error doses of treatment planning software using solid anthropomorphic phantom. J Isfahan Med Sch 2016; 34(393): 908-13. [In Persian].
  6. Shahbazi-Gahrouei D, Gookizadeh A, Abdollahi M. Comparison of conventional radiotherapy techniques with different energies in treating prostate cancer, employing a designed pelvis phantom. J Med Sci 2008; 8(4): 429-32.
  7. Shahbazi-Gahrouei D, Ayat S. Determination of Organ Doses in Radioiodine Therapy using Monte Carlo Simulation. World J Nucl Med 2015; 14(1): 16-8.
  8. Shahbazi D, Khosravi M, Jabbari K. Measurement of photoneutron dose in the linear accelerator at the radiation therapy section of Seyed-Al-Shohada Hospital, Isfahan, Iran. J Isfahan Med Sch 2012; 29(166): 2330-9. [In Persian].
  9. Karbalaee M, Shahbazi-Gahrouei D, Tavakoli MB. An approach in radiation therapy treatment planning: A fast, GPU-based Monte Carlo method. J Med Signals Sens 2017; 7(2): 108-13.
  10. Aspradakis MM, McCallum HM, Wilson N. Dosimetric and treatment planning considerations for radiotherapy of the chest wall. Br J Radiol 2006; 79(946): 828-36.
  11. Hehr T, Budach W, Durst I, Glocker S, Classen J, Weinmann M, et al. Postmastectomy electron-beam-rotation irradiation in locally advanced breast cancer prognostic factors of locoregional tumor control. Strahlenther Onkol 2002; 178(11): 624-32.
  12. Shahbazi-Gahrouei D, Baradaran-Ghahfarokhi M. Assessment of entrance surface dose and health risk from common radiology examinations in Iran. Radiat Prot Dosimetry 2013; 154(3): 308-13.
  13. Shahbazi-Gahrouei D, Gookizadeh A, Sohrabi M, Arab Z. Normal tissues absorbed dose and associated risk in breast radiotherapy. J Radiobiol 2015; 2(1): 16-17.
  14. Gerbi BJ, Antolak JA, Deibel FC, Followill DS, Herman MG, Higgins PD, et al. Recommendations for clinical electron beam dosimetry: supplement to the recommendations of Task Group 25. Med Phys 2009; 36(7): 3239-79.
Journal of Isfahan Medical School
Volume 35, Issue 437 - Serial Number 437
May and June 2017
Pages 796-800

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History

  • Receive Date: 03 May 2017
  • Revise Date: 06 May 2024
  • Accept Date: 06 April 2022

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