Table 6.
Breast size and selected dose-volume parameters for the whole heart and cardiac substructures
| Small CTV | Medium CTV | Large CTV | |||||
|---|---|---|---|---|---|---|---|
| Parameter | p value | ||||||
| 3D-CRT | t-IMRT | 3D-CRT | t-IMRT | 3D-CRT | t-IMRT | ||
| MWHD [Gy] | 1.29 (0.61–3.75) | 1.99 (1.06–3.98) | 2.05 (1.06–3.84) | 2.11 (1.62–3.54) | 2.26 (1.04–4.14) | 2.72 (1.46–4.4) | < 0.005*; 0.047† |
| Heart-V5 Gy [%] | 2.56 (0.02–10.84) | 3.77 (0.1–11.01) | 4.99 (0.59–10.87) | 4.34 (1.19–9.58) | 5.29 (0–12.81) | 6.19 (0.04–12.83) | 0.043* |
| Heart-V10 Gy [%] | 1.28 (0–7.91) | 2.01 (0–7.59) | 2.71 (0.01–7.73) | 2.24 (0.12–68.14) | 3.09 (0–8.24) | 3.17 (0–8.54) | NS |
| Heart-V17 Gy [%] | 0.76 (0–6.61) | 1.22 (0–6.08) | 2.03 (0–6.52) | 1.36 (0–4.79) | 2.37 (0–6.92) | 3.36 (0–6.42) | NS |
| Heart-V20 Gy [%] | 0.62 (0–6.22) | 1 (0–5.63) | 1.83 (0–6.16) | 1.17 (0–4.38) | 2.15 (0–6.51) | 2.01 (0–5.81) | NS |
| Heart-V35 Gy [%] | 0.15 (0–4.12) | 0.2 (0–3.4) | 0.93 (0–4.15) | 0.31 (0–2.3) | 1.06 (0–4.32) | 0.63 (0–2.91) | NS |
| Heart-V40 Gy [%] | 0.02 (0–1.41) | 0.01 (0–1.65) | 0.24 (0–1.45) | 0.03 (0–0.42) | 0.03 (0–1.93) | 0.04 (0–1.69) | NS |
| LV-Dmean [Gy] | 2.3 (0.7–5.7) | 2.9 (1.31–5.84) | 3.2 (1.1–6.9) | 3.15 (1.78–5.97) | 3.5 (1.3–8.0) | 3.92 (1.83–7.25) | 0.019* |
| LV-V5 Gy [%] | 6.8 (0–17.4) | 8.27 (0–17.39) | 9.7 (0–22.0) | 8.47 (0.46–19.87) | 10.8 (0–26.3) | 12 (0–26.02) | 0.052* |
| LV-V23 Gy [%] | 1.4 (0–9.5) | 1.73 (0–8.47) | 2.8 (0–12.0) | 1.81 (0–8.18) | 3.3 (0–14.3) | 3.1 (0–10.58) | NS |
| LV anterior-Dmean [Gy] | 3.6 (1.2–12.8) | 4.86 (1.94–12.35) | 6.8 (2.0–15.9) | 5.71 (2.69–14.48) | 6.8 (1.9–20.1) | 6.94 (2.58–19.18) | 0.017* |
| LV lateral-Dmean [Gy] | 1.6 (0.7–2.8) | 2.16 (1.18–3.38) | 1.8 (0.9–6.3) | 2.24 (1.55–5.12) | 2.5 (1.2–8.7) | 2.98 (1.73–7.59) | < < 0.0010.001*, † |
| LV inferior-Dmean [Gy] | 0.5 (0.3–3.3) | 0.96 (0.77–1.17) | 0.6 (0.5–0.9) | 1.07 (0.9–1.32) | 0.8 (0.6–2.0) | 1.33 (0.96–1.98) | < < 0.0050.005*, † |
| LV septal-Dmean [Gy] | 1.2 (0.4–3.4) | 1.8 (1.01–3.71) | 1.6 (1.1–3.4) | 2.19 (1.77–3.74) | 1.9 (1.2–3.9) | 2.56 (1.72–4.46) | < < 0.0050.005*, † |
| LV apical-Dmean [Gy] | 6.9 (1.2–19.6) | 8.54 (1.64–19.79) | 9.0 (1.7–21.9) | 8.42 (2.46–19.68) | 9.5 (1.2–24.8) | 8.91 (1.76–22.16) | NS |
| LADCA-Dmean [Gy] | 5.2 (1.2–27.9) | 6.84 (1.8–27.62) | 13.8 (2.6–25.2) | 10.76 (3.01–20.73) | 11.1 (2.2–21.2) | 8.24 (2.84–21.22) | NS |
| LADCA-V30 Gy [%] | 0.2 (0–66.3) | 0.36 (0–63.48) | 17.8 (0–59.0) | 7.39 (0–84.2) | 8.9 (0–43.3) | 2.13 (0–46.34) | NS |
| LADCA-V40 Gy [%] | 0 (0–37.8) | 0 (0–43.09) | 0.5 (0–32.9) | 0 (0–3.22) | 0 (0–19.2) | 0 (0–7.26) | NS |
| LADCA-prox-Dmean [Gy] | 1.6 (0.6–8.6) | 2.22 (1.22–7.95) | 2.9 (0.6–7.2) | 2.96 (1.96–5.19) | 2.5 (1.4–7.2) | 2.84 (2.07–12.43) | < 0.001*, 0.002† |
| LADCA-mid-Dmean [Gy] | 7.9 (1.6–40.0) | 9.12 (2.26–39.63) | 17.9 (2.0–38.7) | 13.81 (4.22–30.95) | 10.4 (2.5–29.8) | 11.14 (3.23–36.01) | NS |
| LADCA-dist-Dmean [Gy] | 5.5 (1.4–41.1) | 8.58 (2.03–40.65) | 26.9 (3.5–39.4) | 17.46 (3.98–35.39) | 14.0 (2.4–39.7) | 16.32 (2.87–34.95) | NS |
*intergroup comparison within 3D-CRT technique, using Kruskal-Wallis test; † intergroup comparison within t-IMRT technique using Kruskal-Wallis test; 3D-CRT = three-dimensional conformal radiotherapy; CTV = clinical target volume; Dmean = mean dose; dist = distal; Gy = Gray; LADCA = left anterior descending artery; LV = left ventricle; mid = middle; MWHD = whole heart mean dose; NS = not significant; prox = proximal; t-IMRT = tangential intensity modulated radiation therapy; Vx Gy = fractional volume receiving x Gy