Dosimetric Comparison of 3D Conformal and VMAT with DIBH for Right Breast Cancer

This study explores the use of the Deep Inspiration Breath Hold (DIBH) technique in radiotherapy for right-sided breast cancer, comparing the dosimetric outcomes of 3D conformal radiation therapy (3DCRT) and volumetric modulated arc therapy (VMAT). Using a retrospective design, ten patients with prior left breast DIBH scans were analyzed to assess right breast radiation dose distributions to critical organs at risk (OARs), including the heart, lungs, liver, and contralateral breast. Each patient’s treatment plan was developed for both VMAT and 3DCRT using Varian Eclipse software. The results show that 3DCRT significantly lowered mean heart dose (0.56 Gy vs. 1.26 Gy, p=0.002) and reduced exposure to the left anterior descending artery (LAD), liver, and contralateral breast compared to VMAT. On the other hand, VMAT demonstrated superior sparing of the lung at V20Gy (9.63% vs. 15.07%, p=0.0215) and managed to achieve lower liver maximum doses. The results suggests that 3DCRT could be the better option for patients who are at risk for increased cardiac complication risk due to radiation exposure. While VMAT could offer advantages in reducing lung and liver toxicity for cases where these OARs are of particular concern. Overall, this study highlights the importance of customizing treatment plans to each patient’s needs, as both VMAT and 3DCRT bring unique advantages. Despite the limitations of a small sample size and retrospective design, this study provides valuable insights into the comparative effectiveness of these two techniques. Further studies are encouraged to build on these results, helping to fine-tune treatment approaches for better protection of critical organs and overall patient outcomes in right-sided breast cancer therapy.