Dosimetric Comparison of Treatment of Left Breast Cancer Using 3-Dimention Conformal Radiotherapy Technique (3D-CRT) and Intensity-Modulated Radiotherapy Technique (IMRT)

Document Type : Original Article (s)

Authors

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

2 MSc Student, Department of Medical Physics and Engineering, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran

3 Assistant Professor, Department of Medical Physics and Engineering, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran

4 Radiation Oncologist, Department of Radiation-Oncology, Milad Hospital, Isfahan, Iran

Abstract

Background: Breast cancer is the most common malignant cancer in women, and is the second leading cause of death from cancer in women, after lung cancer. This study compared the dose distribution of left breast as planning target volume (PTV), ipsilateral lung, contralateral lung, heart, and contralateral breast in whole left breast radiotherapy with two general methods, 3-dimention conformal radiotherapy technique (3D-CRT) and intensity-modulated Radiotherapy technique (IMRT) using treatment planning system.Methods: Computed tomography (CT) scan data of 30 patients with left breast cancer with average age of 46 years, candidates for radiotherapy of whole breast, were selected randomly. The left breast contoured as the target and ipsilateral lung, contralateral lung, heart, and contralateral breast contoured as organs at risks according to Radiation Therapy Oncology Group (RTOG) protocol. The 3D-CRT planned with using two tangential opposite beams, depended to patient's anatomy with or without a wedge and using energy of 6 MV. The IMRT treatment plan was optimized by three methods, IMRT-6Field, IMRT-7Field, and IMRT-9Field with energy of 6 MV. Finally, the dosimetric factors of target organ and organs at risk were derived from the dose-volume histogram (DVH) plot, and compared with each other.Findings: The IMRT techniques increased the mean dose of all organs compared to the 3D-CRT technique. From the dosimetric point of view, this was a good indication for target tissue. In the IMRT technique, the volume of the ipsilateral lung that coverage the high doses decreased, and the volume that coverage the lower doses increased compared to 3D-CRT technique. Homogeneity and conformance indexes in IMRT-9Field method were the best, and in 3D-CRT method were the worst among all methods.

Keywords


  1. Siegel RL, Miller KD, Jemal A. Cancer statistics, 2016. CA Cancer J Clin 2016; 66(1): 7-30.
  2. DeSantis CE, Fedewa SA, Goding SA, Kramer JL, Smith RA, Jemal A. Breast cancer statistics, 2015: Convergence of incidence rates between black and white women. CA Cancer J Clin 2016; 66(1): 31-42.
  3. Halperin EC, Brady LW, Perez CA, Wazer DE. Perez and Brady's Principles and Practice of Radiation Oncology. Philadelphia, PA: Lippincott Williams and Wilkins; 2013.
  4. Bartelink H, Maingon P, Poortmans P, Weltens C, Fourquet A, Jager J, et al. Whole-breast irradiation with or without a boost for patients treated with breast-conserving surgery for early breast cancer: 20-year follow-up of a randomised phase 3 trial. Lancet Oncol 2015; 16(1): 47-56.
  5. Kausar M, Gurjar OP, Bagdare P, Gupta KL, Bhandari V, Naik A, et al. Dosimetric analysis of intensity-modulated radiotherapy and three-dimensional conformal radiotherapy for chest wall irradiation in breast cancer patients. Journal of Radiotherapy in Practice 2016; 15(1): 30-7.
  6. Jin GH, Chen LX, Deng XW, Liu XW, Huang Y, Huang XB. A comparative dosimetric study for treating left-sided breast cancer for small breast size using five different radiotherapy techniques: conventional tangential field, filed-in-filed, tangential-IMRT, multi-beam IMRT and VMAT. Radiat Oncol 2013; 8: 89.
  7. Xu D, Li G, Li H, Jia F. Comparison of IMRT versus 3D-CRT in the treatment of esophagus cancer: A systematic review and meta-analysis. Medicine (Baltimore ) 2017; 96(31): e7685.
  8. Yim J, Suttie C, Bromley R, Morgia M, Lamoury G. Intensity modulated radiotherapy and 3D conformal radiotherapy for whole breast irradiation: a comparative dosimetric study and introduction of a novel qualitative index for plan evaluation, the normal tissue index. J Med Radiat Sci 2015; 62(3): 184-91.
  9. Darby SC, Ewertz M, McGale P, Bennet AM, Blom-Goldman U, Bronnum D, et al. Risk of Ischemic Heart Disease in Women after Radiotherapy for Breast Cancer. N Engl J Med 2013; 368(11): 987-98.
  10. Drzymala RE, Mohan R, Brewster L, Chu J, Goitein M, Harms W, et al. Dose-volume histograms. Int J Radiat Oncol Biol Phys 1991; 21(1): 71-8.
  11. Mayles P, Nahum A, Rosenwald JC. Handbook of radiotherapy physics: Theory and practice. Boca Raton, FL: CRC Press; 2007.
  12. White J, Tai A, Arthur D, Buchholz T, MacDonald S, Marks L, et al. Breast cancer atlas for radiation therapy planning: Consensus definitions. Philadelphia, PA: Radiation Therapy Oncology Group (RTOG); 2014.
  13. NRG Oncology. RTOG 1005; A phase III trial of accelerated whole breast irradiation with hypofractionation plus concurrent boost versus standard whole breast irradiation plus sequential boost for early-stage breast cancer. [Online]. [cited 2014 July 31]; Available from: URL: https://www.rtog.org/clinicaltrials/protocoltable/studydetails.aspx?action=openFile&FileID=9366.