Fig. 3

a Dose difference distributions of the cross-sectional plane for a typical patient with left-side breast cancer after BCS. The dose difference was calculated by subtracting Plan- (calculated without immobilization devices) from Plan+ (calculated with the whole immobilization devices included in the external body structure). b DVH results of Plan- and Plan+ for a typical patient with left-side breast cancer after BCS. The solid and dotted lines represent the results of Plan- and Plan+, respectively