This study is designed to explore whether we can use the same images obtained at simulation to potentially screen for abnormal lung or heart imaging findings.

The American Cancer Society predicts that for women, there will be more than 120,000 cases of lung and bronchus cancer in 2023. Even for women who don't smoke, the risk of lung cancer is still increasing, suggesting there might be other factors involved that we need to understand better. When lung cancer is caught early, it's more likely to be treatable and people have a better chance of surviving. Studies in 2006 and 2011 found that using a special kind of scan called low-dose CT (LDCT) can help detect lung cancer early, making it potentially curable and reducing the risk of death. 

Patients will be referred to radiation oncology for breast radiotherapy as part of their routine medical care. All patients who are seen for radiotherapy will undergo CT simulation for radiation therapy planning purposes. At this time, patients will be approached to participate in this study.