This study aims to discover more about radiation techniques for people treated for left-sided breast cancer that minimizes exposure to the heart, as noted by mean heart dose. Both prone (lying face down) radiation and Deep Inspiration Breath Hold (DIBH) are more labor-intensive and usually require longer treatment times for patients than traditional supine (lying face up) free-breathing radiation treatments. Thus, identifying people that benefit most from these techniques can better utilize resources. This study compares supine and prone positioning, with or without DIBH, to further assess which positioning technique will achieve the lowest cardiac radiation doses.
