A hearty dose of radiation.

Despite the recent hoopla surrounding cardiac SBRT, we’ve actually been irradiating the heart for quite some time now. The newest (yet still amazingly old) Darby study of heart dose from breast radiation provides a detailed analysis of future cardiovascular events, and it can be boiled down to three main ideas. First, there is no minimum threshold below which there are no potential cardiovascular consequences. Second, the proportional dose increase in any part of the heart proportionally increases the risk of an event in that location. In other words, a higher than usual dose to the septal portion of the left ventricle means that anatomic location has a proportionally higher risk of an event. Third, radiation can't be completely blamed for these events.  TBL: Here's a reminder that radiation dose modifies baseline risk of future cardiovascular events, meaning careful consideration of overall cardiac risk is important when considering dosimetry to all parts of the heart. | Taylor, J Clin Oncol 2018