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Table 2 Comparison of average dose parameters for targets and OARs for left-sided breast cancers by treatment cohort

From: Cardiac dose reduction with deep inspiration breath hold for left-sided breast cancer radiotherapy patients with and without regional nodal irradiation

Parameter WBRT WBRT FB vs. DIBH p-value* B/CWRT + RNI B/CWRT FB vs. DIBH p-value*** All Patients FB vs. DIBH
p-value*
CTVb Volume (cc)       
 FB 515.5 ± 356.9 0.577 489.2 ± 200.8 0.496 503.7 ± 290.2 0.349
 DIBH 511.8 ± 354.6 491.3 ± 218.6 502.6 ± 294.0
D95 for CTVb (%)       
 FB 97.3 ± 1.4 0.286 92.2 ± 8.1 0.030 95.0 ± 5.9 0.013
 DIBH 97.7 ± 1.3 96.2 ± 3.0 97.0 ± 2.3
V80 IMC (%)       
FB N/A N/A 99.7 ± 0.9 1.000 N/A N/A
DIBH N/A   98.9 ± 3.3 N/A
Dmean Heart (cGy)       
 FB 166.1 ± 71.0 0.001** 375.7 ± 186.0 0.004** 260.5 ± 169.3 <0.001**
 DIBH 110.8 ± 32.1 145.0 ± 37.7 126.2 ± 38.0
V25 Heart (%)       
FB 0.8 ± 1.4 0.059 4.0 ± 3.4 0.014 2.2 ± 2.9 0.002**
DIBH 0.1 ± 0.4 0.0 ± 0.1 0.1 ± 0.3
Dmean LAD (cGy)       
 FB 1004.6 ± 892.4 0.002** 1802.8 ± 917.8 0.004** 1363.8 ± 969.4 <0.001**
 DIBH 420.0 ± 277.4 396.2 ± 81.5 409.3 ± 208.4
V20 Left Lung (%)       
 FB 10.5 ± 4.6 0.067 18.3 ± 5.1 0.250 14.0 ± 6.2 0.029
 DIBH 8.5 ± 3.6 16.3 ± 2.8 12.0 ± 5.1
Patients meeting       
Dmean < 4Gy (fraction, %)       
 FB 11/11 (100) N/A 5/9 (56) 0.134 16/20 (80) 0.134
 DIBH 11/11 (100) 9/9 (100) 20/20 (100)
  1. Wilcoxon signed-rank test is used for comparison of all continuous variables, and McNemar's test is applied for discrete variables
  2. Significant p-values after adjusting for multiple testing are indicated by a double asterisk (**)
  3. Abbreviations: WBRT = whole breast RT ± boost cohort, B/CWRT + RNI = breast or chest wall + regional nodal RT cohort, FB = free-breathing, DIBH = deep inspiration breath hold, CTVb = CTV for breast or chest wall, IMC = internal mammary chain nodes, D95 = Dose to 95 % target volume,V80 = % volume of organ receiving 80 % of the prescription dose, V25 = % volume of organ receiving 25 Gy, Dmean = Mean dose, LAD = left anterior descending coronary artery, V20 = % volume of organ receiving 20 Gy, N/A = not applicable. Data shown are mean values with one standard deviation. *In this group, to achieve significance p-values must be < 0.0083 to account for multiple testing. ***In this group, to achieve significance p-values must be < 0.0071 to account for multiple testing. **Indicates significance when compared to the Bonferroni adjusted criterion