Granted adequate target coverage, do you constrain dose to sub-volumes of the heart when treating locally advanced lung cancer?

This is a very important question that recent data is beginning to shed light on. It’s difficult to address cardiac sub-structures without first talking about mean heart dose, its evolution, and the relationship with baseline cardiac risk. While MHD certainly has its limitations, there is a utility in acknowledging that current dose limits (e.g., mean heart dose <20 Gy) are simply too high (when can be avoided/minimized). Even lower cutoffs, such as MHD >10 Gy, have been associated with major adverse cardiac events (MACE) and mortality in a large cohort of locally advanced NSCLC patients (Atkins et al. JACC 2019). Importantly, there is an interaction with heart dose and baseline cardiac risk, such that the impact of an increased dose is mos...