Fig. 2.

(A) Weekly percent changes, relative to baseline, in absolute lymphocyte counts (ALCs) for patients treated with protons and photons. The P-values reflect the significance of differences between protons and photons. (B) Scatter plot of % differences between baseline and posttreatment ALCs (Δ-ALC) for each treatment modality as a function of PTV. A larger PTV means greater decline in ALCs over the course of radiotherapy. (C) Mean Δ-ALC for photon and proton populations are significantly different even though the baseline ALCs are essentially the same (Table 2).