1. Prediction Models of Cardiac Sparing during Deep Inspiration Breath-Hold in Left-Sided Breast Cancer with Internal Mammary Node Irradiation.
- Author
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Sun, X., Zhang, Y., Wu, X., and Zhou, Y.
- Subjects
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PEARSON correlation (Statistics) , *MEDICAL dosimetry , *INTENSITY modulated radiotherapy , *COMPUTED tomography , *BREAST cancer - Abstract
Deep inspiration breath hold (DIBH) can effectively reduce doses to the heart and coronary left anterior descending (LAD) undergoing left-sided breast radiation therapy; however, there is limited information on studies of the breast/chest wall plus internal mammary node irradiation (IMNI). Therefore, the aim of this study is to evaluate the cardiac dosimetric advantages of DIBH in postoperative left-sided breast cancer patients undergoing IMNI and construct prediction models using factors influenced cardiac sparing through DIBH. Forty-five postoperative left-sided breast cancer patients receiving IMNI were collected in this study continuously, and two simulated computed tomography (CT) scans were performed in the free breathing (FB) and DIBH. Intensity-modulated radiotherapy (IMRT) plans were generated on DIBH scans. Anatomical parameters were measured based on the FB planning CT scans. Dosimetric parameters were then compared between DIBH and FB, and predictors of cardiac sparing during DIBH were analyzed. Comparison of dosimetric variables was performed using paired t test, bivariate correlation was evaluated using Pearson correlation, and independent factors and constructed models were obtained using multiple linear regression. Compared to FB, DIBH reduced the dose parameters of D mean , D max , and V 5 -V 30 for the heart, LAD and left lung significantly (P < 0.05). A significant correlation was observed between cardiac contact distance in the axial (CCDax) (r = 0.35), cardiac contact distance in the parasagittal (CCDps) (r = 0.40), lateral heart-to-chest distance (HCD) (r = -0.34), breast volume (BV) (r = 0.52), left lung volume (LV) (r = -0.50), and age (r = -0.43) with reduction in mean heart dose (P < 0.05), whereas initial LAD-to-manubrium distance (LMD) (r = -0.57), BV (r = 0.34), LV (r = -0.34), and age (r = -0.43) were strongly (P < 0.05) correlated with mean LAD dose reduction. Multiple linear regression results showed that BV, age and CCDps were related to mean heart dose reduction independently (P < 0.05), while LMD, BV, and age were identified as independent predictors of mean LAD dose reduction (P < 0.05). Mathematical prediction models were developed to predict cardiac sparing. DIBH could effectively reduce the radiation dose for both of heart and LAD in postoperative left-sided breast cancer patients undergoing IMNI. The mathematical prediction models using BV, age, LMD and CCDps may help identify patients most likely to benefit from DIBH. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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