Lymphopenia During RT
The number of patients with grade 3 or 4 lymphopenia during RT as well as the median ALC of all patients during RT is shown in Figs. 1and 2 and Supplemental Table 1 . Seventy-eight percent of patients (40/51) had at least grade 3 lymphopenia by week 3 of RT, but 51% (24/47) had improved to grade 2 or lower lymphopenia by week 5. Similarly, the lowest median ALC occurred during week 3 of RT. Of note, not all 54 patients in our cohort had lymphocyte counts checked each week (see Supplemental Table 1 ). The degree of lymphopenia was greater in those patients who received a higher craniospinal dose (Figs. 1 and 2 ).