Meaningless meaning of the mean.

Say that three times fast. The clinical utility of mean heart dose as a way to assess future risk of cardiac events was born in the era of conventional fields (aka homogenous doses). This simple yet pragmatic dosimetric study demonstrates very little correlation between mean dose to the heart as a whole and mean doses to critical cardiac subsites when using modern conformal (read: heterogenous) dose distributions, most notably proton therapy which is often used for mediastinal sites in younger patients. | Hoppe, Pract Radiat Oncol 2019