Forecasting time-dependent radiation induced lymphocyte depletion in a clinical trial on early-stage lung cancer

Radiation-induced lymphocyte depletion varies substantially among patients receiving SBRT for early-stage lung cancer. We developed a model to predict time-dependent lymphocyte kinetics using a coupled surrogate of blood and lymphatic flow. After optimizing the model using retrospective data, we tested it on a two-arm clinical trial cohort with patients receiving standard of care and novel immune-sparing treatment plans. The mechanistic model forecasted absolute lymphocyte count up to six-months post treatment and shed light on how irradiation of lymphatic tissues impacts severity and timing of immune nadirs.