Top Line: There are many reasons not to love treating a huge locally-advanced lung cancer with definitive radiation, not least of which is cardiac morbidity.
The Study: There are countless studies demonstrating dosimetric predictors of cardiac events, but that doesn’t really help you when there’s central disease you still have to treat. Here is a very practical secondary analysis (of a photon versus proton trial) demonstrating the predictive power of an already readily-available lab test: high-sensitivity cardiac troponin T (hs-cTnT). Among 225 patients prospectively evaluated with this lab before, during and after definitive chemoradiation of locally-advanced non-small cell lung cancer, risks of grade 3+ cardiac toxicity (n=24) or mortality (n=9) were significantly increased if the pretreatment hs-cTnT was >10 ng/L or if the increase during treatment was ≥5 ng/L. Side bar: mean heart dose was less with proton therapy but this did not translate to any difference in cardiac events.
TBL: Whether or not you can meaningfully modify heart dose from the get-go, this easily implementable strategy can help identify patients in need of early cardiac monitoring and/or intervention. | Xu, Int J Radiat Oncol Biol Phys 2021