Iranian Journal of Medical Physics

Iranian Journal of Medical Physics

Assessment of Dose Distribution and Organ-at-Risk Exposure in VMAT Versus 3D-CRT for Right Breast Cancer

Document Type : Original Paper

Authors
Mohamed Khairat Allah 1
Atmane Rane 2
Abdellah Halimi 1
Youssef Bouzekraoui 1
Hicham Asmi 3
Khalid Elouardy 4
1 Hassan First University of Settat, High Institute of Health Sciences, Laboratory of Sciences and Health Technologies, Settat, Morocco
2 Sciences, Innovation and Sustainable Development - Multidisciplinary Faculty of Khouribga
3 Laboratoire de Physique des Hautes Énergies,. Modélisation et Simulation
4 Radiophysician
10.22038/ijmp.2025.89429.2578
Abstract
Introduction: Breast cancer is one of the most common malignant tumors worldwide, and radiotherapy plays a crucial role in its treatment. This study compares Volumetric Modulated Arc Therapy (VMAT) and Three-Dimensional Conformal Radiotherapy (3D-CRT) for right-sided breast cancer treatment, focusing on dosimetric parameters.
Material and Methods: This retrospective study included 20 patients with right breast cancer treated at the International Hospital of Khouribga (mean age 52.4 ± 4.9 years; mean body mass index (BMI) 27.2 ± 1.1 kg/m²). For each patient, two treatment plans were generated: VMAT with dual coplanar arc configuration and 3D-CRT with opposed tangential beams. Analyzed parameters included target volume coverage and doses to organs at risk.
 Results: VMAT provided superior target coverage and dose conformity. The mean homogeneity index (HI) was lower with VMAT (0.08 ± 0.02) than 3D-CRT (0.14 ± 0.02), and the conformity index (CI) was higher (0.99 ± 0.01 vs. 0.96 ± 0.02). Mean heart dose was 4.9 ± 0.7 Gray (Gy) with VMAT versus 1.0 ± 0.2 Gy with 3D-CRT; ipsilateral lung mean dose was 13.7 ± 1.5 Gy versus 11.9 ± 0.7 Gy, respectively. Contralateral organs received higher low-dose exposure with VMAT. VMAT achieved improved planning target volume (PTV) coverage and conformity, whereas 3D-CRT provided better contralateral organ sparing.
 Conclusion: This study demonstrates VMAT's dosimetric advantages over 3D-CRT for breast cancer treatment, providing institutional validation for technique selection in resource-limited settings.
Keywords
Breast Neoplasms Radiotherapy
Intensity-Modulated Radiotherapy Conformal Radiotherapy Dosage Planning Computer-Assisted
Subjects
  1. Sung H, Ferlay J, Siegel RL, Bray F, Jemal A, Fitzmaurice C, et al .Global cancer statistics 2020: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin. 2021;71(3):209–
  2. Clarke M, et al. Effects of radiotherapy and of differences in the extent of surgery for early breast cancer on local recurrence and 15-year survival: an overview of the randomized trials. Lancet. 2005;366(9503):2087–
  3. Otto K. Volumetric modulated arc therapy: IMRT in a single gantry arc. Med Phys. 2008;35(1):310–
  4. Virén T, et al. Tangential volumetric modulated arc therapy technique for left-sided breast cancer radiotherapy. Acta Oncol. 2015;54(6):889–
  5. Haciislamoglu E, et al. Evaluation of different radiotherapy techniques for breast cancer treatment: Dosimetric comparison of IMRT, VMAT, and 3D-CRT. Radiat Oncol J. 2020;38(1):30–
  6. Popescu CC, et al. Dosimetric comparison of VMAT and 3D-CRT for breast irradiation. Br J Radiol. 2019;92(1097):20180687.
  7. Rana S, et al. Clinical dosimetric comparison of different breast radiotherapy techniques: IMRT, VMAT, and 3D-CRT. J Med Phys. 2013;38(3):120–
  8. Wang W, et al. Dosimetric comparison of VMAT and 3D-CRT for breast cancer and implications for cardiac and lung doses. Front Oncol. 2021;11:661220.
  9. Darapu A, et al. Comparative dosimetric study of VMAT and 3D-CRT for breast cancer radiotherapy. Rep Pract Oncol Radiother. 2020;25(4):532–
  10. International Atomic Energy Agency. IAEA Human Health Report No. 10: Transition from 2-D Radiotherapy to 3-D Conformal and IMRT Techniques. Vienna: IAEA; 2014.
  11. Radiation Therapy Oncology Group (RTOG). Breast Cancer Atlas for Radiation Therapy Planning: Consensus Definitions. 2016.
  12. International Atomic Energy Agency. Accuracy Requirements and Uncertainties in Radiotherapy. Vienna: IAEA; 2012.
  13. Radiation Therapy Oncology Group (RTOG). NRG Oncology Protocol 1005. 2018.
  14. International Commission on Radiation Units and Measurements. ICRU Report 83: Prescribing, Recording, and Reporting Photon-Beam Intensity-Modulated Radiation Therapy (IMRT). Bethesda, MD; 2010.
  15. Feng M, et al. Development and validation of field-in-field technique for breast IMRT. Pract Radiat Oncol. 2011;1(2):72–
  16. Offersen BV, et al. ESTRO consensus guidelines on target volume delineation for elective radiation therapy of early-stage breast cancer. Radiother Oncol. 2022;167:109–
  17. Bush K, et al. Monte Carlo dose calculation for IMRT and VMAT planning. Med Phys. 2008;35(10):4331–
  18. Van Esch A, et al. The use of the γ-evaluation method for dose distribution comparison. Phys Med Biol. 2006;51(14):N309–
  19. Feuvret L, et al. Conformity index: A review. Cancer Radiother. 2006;10(5):295–
  20. Paddick I. A simple scoring ratio to index the conformity of radiosurgical treatment plans. J Neurosurg. 2000;93(3 Suppl):219–
  21. Johansen S, et al. Comparison of VMAT and 3D-CRT for breast cancer radiotherapy: A dosimetric and clinical evaluation. Acta Oncol. 2021;60(5):599–
  22. Klein EE, et al. Task Group 142 report: Quality assurance of medical accelerators. Med Phys. 2009;36(9):4193–
  23. McDonald MW, et al. Statistical methods in radiation oncology: Comparing dosimetric data. Pract Radiat Oncol. 2013;3(4):e229–
  24. Taylor CW, et al. Cardiac dose from breast cancer radiotherapy in 2010–2015: Population-based estimates. J Clin Oncol. 2017;35(13):1390–
  25. Jimenez RB, et al. Assessment of skin dose and toxicity in modern breast radiotherapy. Pract Radiat Oncol. 2021;11(3):e226–
  26. Kim H, et al. Skin dose and acute toxicity in breast VMAT versus 3D-CRT. Radiat Oncol J. 2018;36(3):199–210
Iranian Journal of Medical Physics
Volume 23, Issue 1
January and February 2026
Pages 18-25

  • Receive Date 24 July 2025
  • Revise Date 17 February 2026
  • Accept Date 23 November 2025