Preventing Cardiotoxicity in Personalized Breast Irradiation

Area of Science:

• Radiation Oncology
• Medical Physics
• Cardiovascular Health in Cancer Care

Background:

• Assessing the benefits of Deep Inspiration Breath Hold (DIBH) over standard radiotherapy techniques.
• Identifying patient-specific factors influencing the Left Anterior Descending (LAD) artery dose during breast irradiation.

Purpose of the Study:

• To evaluate the dosimetric advantage of DIBH for left-sided breast cancer patients.
• To determine predictors of LAD dose in DIBH and free-breathing (FB) radiotherapy plans.

Main Methods:

• Analysis of 197 left-sided breast cancer patients with both DIBH and FB radiotherapy plans.
• Receiver Operating Characteristic (ROC) analysis to identify parameters predicting LAD dose thresholds.
• Calculation of Area Under the Curve (AUC) and post-test probability for parameter combinations.

Main Results:

• DIBH plans significantly reduced LAD maximum dose by 31.7% (3.5 Gy vs. 4.8 Gy) and mean dose by 28.1% (8.2 Gy vs. 12.8 Gy) compared to FB.
• Minimum LAD distance to tangent open fields was the strongest predictor of LAD dose.
• Lung volume, heart volume, and breast separation were also identified as predictive parameters.

Conclusions:

• DIBH offers a clear dosimetric advantage for reducing LAD dose in all patients.
• DIBH should be the preferred radiotherapy technique for left-sided breast cancer to protect the heart.