Target volume coverage for treatment plans across consensus guidelines. NS, not statistically significant with P > .05. ∗Radiation Technology Oncology Group versus European Society for Radiation therapy and Oncology P < .05; †Radiation Technology Oncology Group versus institutional variation, P < .05. Ax, undissected axillary lymph nodes; Clung V5, contralateral lung volume receiving 5 Gy; CW, chest wall. IMN, internal mammary lymph nodes; LAD, left anterior descending artery; Lung V5, ipsilateral lung volume receiving 5Gy; Lung V10, ipsilateral lung volume receiving 10 Gy; lung V20, ipsilateral lung volume receiving 20 Gy; SCL, supraclavicular lymph nodes; V15, volume receiving 15 Gy; V25, volume receiving 25 Gy; V30, volume receiving 30 Gy.