Immune EIDCt.

Radiation-induced lymphopenia has long been on the wrong side of the double-edged sword of radiation’s impact on the immune system. There is a complicated formula to produce a measure called the “estimated dose to immune cells,” or EDIC for short, heavily based on mean doses to heart, lung and liver weighted by estimated blood volume circulating through each organ. EDIC has already been shown to be an important predictor of lymphopenia following definitive radiation for non-small cell lung cancer. Here we have a retrospective look at the impact of EDIC following chemoradiation for locally-advanced esophageal cancer. Among 344 patients, median EDIC was 3.4 Gy, and those with higher EDIC (>4 Gy) had significantly higher rates of grade lymphopenia (67%) than those with lower (40%). What’s more, on multivariate analysis, higher EDIC was independently associated with worse progression-free, mets-free and overall survival in a continuous fashion. TBL: EDIC again appears to be a modifiable measure of radiation’s crucial impact on patient immune systems. | Xu, Radiother Oncol 2020