Effect of Three-dimensional conformal radiotherapy with full beam ‎size technique on clinical outcomes for patients with left breast cancer

Document Type : Research Paper


Department of Basic Sciences, College of Medicine, Hawler Medical University, Erbil, Kurdistan Region-Iraq


Background and objectives: Three-dimensional conformal radiotherapy (3DCRT) is used to treat breast cancer with multiple radiation beam fields with precision while sparing normal tissue. Noteworthy problem with treatment using different isocenters in 3DCRT technique is undesirably increased radiation doses due to superposition of fields of radiation beams. At this condition, the use of a single isocenter appears to be a suitable solution. The objective of this study was to evaluate the clinical outcomes of 3DCRT with full beam technique (single isocenter) and evaluate effect high-energy photon beam during whole breast irradiation on healthy tissues, planning target volume, dose homogeneity, and dose of organs at risk (such as heart, cord, right and left lungs, and spinal cord).
Methods: Radiotherapy treatment of 50 patients with left-sided breast cancer treated to a prescribed dose of 40.05 Gy in 20 fractions, 5 fractions per week during 4 weeks. The treatment plans executed by using Linear accelerator (Elekta Synergy) with single isocenter for evaluation of clinical outcomes based on three-dimensional conformal radiotherapy (3DCRT) technique with full beam plan.
Results: Mean dose Gy for planning target volume PVT was (40.53± 0.46 Gy). The dose for complete beam planning methods was 40.050Gy, and Conformity Index CI < 1. The mean heart doses were (476.7±314.6 cGy), and the heart was exposed to dose 4.4±4.5 cGy. The low dose volume in this technique was less than <20 Gy. Similarly, the left lung was exposed to the low dose volume (V20) was 0.020 cGy, but for the right lung (V20) was zero. The mean dose of the left lung was (10.18Gy), but with the right lung was (0.0882 Gy). The Spinal Cord Max dose <2 Gy
Conclusion: Complete planning treatment plan achieved improved dose homogeneity and superior outcome regarding dose to normal tissues.