A Comparative Study of 3-D Conformal Radiotherapy Treatment Plans with and Without Deep Inspiration Breath-Hold Technique for Left-Sided Breast Cancer

Introduction: The rate of cardiac diseases have increased among patients who underwent radiotherapy for left-sided breast cancer. The study’s aim was evaluate the dose to organs at risk in free-breathing 3-dimensional conformal (FB-3DCRT) against 3-dimensional conformal deep inspiration breath-hold (3DCRT-DIBH) in patients with left-sided breast cancer. Material and Methods: In total, 15th female patients diagnosed with left-sided breast cancer were included in this study from December 2017 to December 2018. All selected patients were subjected to FB and DIBH computed tomography (CT) scans. The 3DCRT plans were created on both DIBH and FB scans for each selected patient. Various doses were obtained from dose-volume histograms and then compared. The data were analyzed in SPSS software (version 20) (IBM; IL). P-value less than 0.05 was considered statistically significant. Results: The results obtained from the DIBH and FB conditions were compared. The average maximum dose and V95% for planning target volume  was approximate for both DIBH and FB, and the average mean doses to the heart, left anterior descending artery, and left lung were decreased by 40.50% (P=0.0003), 54.30% (P=0.02),and 18.50% (P=0.0002) in DIBH, respectively. Moreover, the heart V25% and V30% were decreased by 36% (P=0.06) and 35.8 % (P=0.03) in DIBH, respectively. Regarding the left lung, a decrease by 18.10% in V10% (P=0.0006) and 18% in V20% (P=0.0002) was also observed in DIBH. Conclusion: The 3DCRT-DIBH for patients with left-sided breast cancer maintained the benefits of radiotherapy while minimizing cardiac risks. All patients completed their treatment smoothly.