(a) Breast skin DVH comparison: comparison of the breast skin DVH for the C-arm linac (yellow), Halcyon (dark yellow), C-arm linac with bolus applied every other day (orange), and C-arm linac with bolus (red). The dashed curve and bands represent the average and 1 sigma variation of the DVHs across all 14 patients in the planning study. (b) Breast skin dosimetry: comparison of Dmax, Dmean, and V70%Rx of the breast skin structure calculated in eclipse for the same 4 scenarios. DVH = dose volume histogram.