| Comparison of Different Radiotherapy Techniques in Breast Cancer using Active Breathing Coordinator. |
| Paper ID : 1067-ISCH |
| Authors |
|
Yara Gamal Farid *1, Mohamed Saber2, Magdy Khalil3, Medhat Shafaa4, Khalid Khalil5 1Faculty of Science, Helwan University 2Medical Physics Department, Maadi Military Hospital and Air Force Specialized Hospital, Cairo, Egypt 3School of Allied Health Sciences, Badr University in Cairo (BUC), Badr City and Department of Physics, Faculty of Science, Helwan University, Cairo, Egypt 4Medical Biophysics, Department of Physics, Faculty of Science, Helwan University, Cairo, Egypt 5Clinical Oncology Department, Kasr Alainy Center of Clinical Oncology, Cairo University, Cairo, Egypt. |
| Abstract |
| Background: Radiotherapy is crucial for managing left-sided breast cancer but it elevates the risk of cardiac and pulmonary damage impacting the heart and left anterior descending (LAD) artery. The Deep Inspiration Breath Hold (DIBH) technique using an Active Breathing Coordinator (ABC) system significantly reduces cardiac dose. This study compares three planning techniques—3D Conformal Radiotherapy (3DCRT), Intensity-Modulated Radiotherapy (IMRT), and Volumetric-Modulated Arc Therapy (VMAT)—under ABC conditions. Methods: A retrospective study of 30 early-stage left-sided breast cancer patients treated with ABC-assisted DIBH was conducted. Each patient had three plans: 3DCRT, IMRT, and VMAT, prescribing 40.05 Gy in 15 fractions. Planning target volume (PTV) coverage and organs-at-risk (OARs) doses were assessed using dose-volume histograms. Parameters included V95, D98, D50, D2, V107, conformity index (CI), homogeneity index (HI), and OAR metrics for the heart, LAD, lungs, and contralateral breast. Statistical significance was determined with ANOVA and Friedman tests. Results: VMAT achieved superior PTV coverage and homogeneity (HI= 0.1) compared to IMRT and 3DCRT. Mean heart dose was lowest for 3DCRT (1.9 Gy) and VMAT (2 Gy), while LAD doses were significantly lowest with VMAT (Dmean= 5.2 Gy; Dmax= 17.3 Gy, P< 0.001). For ipsilateral lung, 3DCRT provided better low-dose sparing (V5, V10), whereas VMAT minimized high-dose regions (V20). Contralateral organs received the lowest dose with 3DCRT. Conclusion: VMAT provided optimal PTV coverage and cardiac sparing, especially for LAD, while 3DCRT reduced contralateral organ and low-dose lung exposure. IMRT demonstrated moderate outcomes, highlighting the necessity for personalized planning to balance target coverage with OAR protection. |
| Keywords |
| Left-sided breast cancer, Radiotherapy planning, Active Breathing Coordinator (ABC), Deep Inspiration Breath Hold (DIBH), 3DCRT, IMRT, VMAT, Cardiac sparing |
| Status: Abstract Accepted (Poster Presentation) |