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Table 1 The dosimetric comparison for the VMAT versus the IMPT plans

From: Dosimetric evaluation of photons versus protons in postmastectomy planning for ultrahypofractionated breast radiotherapy

Organs Dose levels Lt. chest wall + regional nodes Lt. chest wall Rt. chest wall + regional nodes Rt. chest wall
IMPT VMAT P value IMPT VMAT P value IMPT VMAT P value IMPT VMAT P value
PTV Dmax (GyRBE) 29.0 ± 1.0 28.0 ± 0.8 < 0.05 29.33 ± 1.4 28.1 ± 0.8 < 0.05 28.1 ± 0.8 27.4 ± 0.7 0.1 28.3 ± 1.1 26.4 ± 3.1 0.1
D90 (GyRBE) 25.8 ± 0.3 25.6 ± 0.3 0.2 25.8 ± 0.6 25.4 ± 0.3 < 0.05 25.30 ± 0.51 25.4 ± 0.2 0.4 25.4 ± 0.5 25.3 ± 0.2 0.3
D95 (GyRBE) 24.8 ± 0.1 24.8 ± 0.4 0.9 24.8 ± 0.2 24.7 ± 0.2 0.2 24.6 ± 0.2 24.7 ± 0.3 0.4 24.8 ± 0.5 24.9 ± 0.8 0.6
Ipsi-lung Dmean (GyRBE) 8.3 ± 1.3 7.9 ± 1.7 0.4 7.4 ± 1.9 7.8 ± 0.8 0.5 7.3 ± 1.2 7.9 ± 2.7 0.5 6.9 ± 1.7 8.0 ± 1.2 0.1
V5 (%) 55.1 ± 9.2 54.6 ± 11.9 0.9 49.3 ± 10.5 54.2 ± 7.0 < 0.05 47.6 ± 8.1 57.1 ± 10.9 < 0.05 44.6 ± 10.5 52.7 ± 12.1 0.1
V10 (%) 39.3 ± 7.2 27.3 ± 8.2 < 0.05 33.3 ± 7.7 26.5 ± 4.0 < 0.05 34.8 ± 9.4 31.9 ± 4.5 0.4 29.6 ± 5.4 27.9 ± 6.4 0.4
V20(%) 9.7 ± 3.7 7.6 ± 4.7 < 0.05 8.5 ± 5.9 6.4 ± 3.0 0.2 9.6 ± 3.4 8.2 ± 3.6 0.1 9.6 ± 4.3 8.3 ± 3.9 0.3
Contra-lung Dmean (GyRBE) 0.2 (0.1–0.3) 3.4 (2.9–3.7) < 0.05 0.1 (0.1–0.2) 3.1 (2.7–4.0) < 0.05 0.1 (0.0–0.1) 3.1 (2.9–3.2) < 0.05 0.0 (0.0–0.1) 2.6 (2.4–3.0) < 0.05
V5 (%) 0.6 (0.2–1.2) 20.9 (14.5–25) < 0.05 0.4 (0–0.9) 14.1(11.1–26.8) < 0.05 0 (0–0) 15.8 (12.4–18.7) < 0.05 0 (0–0) 10.9 (9.4–15) < 0.05
V10 (%) 0.1 (0–0.3) 0.9 (0.6–2.1) < 0.05 0 (0–0) 0.8 (0.4–1.5) < 0.05 0 (0–0) 0 (0–0) < 0.05 0 (0–0) 0.4 (0.2–0.6) < 0.05
Heart Dmax (GyRBE) 16.9 ± 7.0 19.9 ± 4.2 < 0.05 16.9 (10.4–25.5) 18.6 (18.3–22.0) 0.3 10.6 ± 4.8 10.1 ± 4.8 0.7 8.4 (4.8–13.4) 11.2 (8.4–14.5) 0.4
Dmean (GyRBE) 1.1 (0.6–2.0) 4.6 (4.4–4.7) 0.1 1.2(0.7–1.5) 5 (4.6–5.6) < 0.05 0.4 (0.3–0.7) 2.8 (2.2–3.4) < 0.05 0.5 (0.2–0.8) 3.3 (2.5–3.5) < 0.05
V5 (%) 7.5 ± 4.0 28.2 ± 10.9 < 0.05 8.6 (4.6–10.2) 33 (26.3–40.2) < 0.05 2.3 (1.6–4.7) 10.6 (5.4–17.1) < 0.05 2.3 (0.5–5.6) 16.3 (6–17.8) < 0.05
V10 (%) 3.5 (1–6.3) 8.5 (7.4–11.8) < 0.05 4 (1.1–5.2) 12 (8.3–14.4) < 0.05 1.2 (0.2–2.2) 1.7 (0–3) 0.64 0.2 (0–1.2) 1.1 (0–2.5) 0.4
V20 (%) 0.4 (0–0.8) 0.5 (0.4–1.7) 0.1 0.3 (0–0.6) 0.5 (0.2–0.6) 0.2 0 (0–0) 0 (0–0) 0.6 0 (0–0.1) 0 (0–0) 0.1
Skin Dmax (GyRBE) 28.4 ± 1.2 27.3 ± 0.9 0.1 28.4 ± 1.9 27.3 ± 0.8 < 0.05 28.2 ± 1.1 26.8 ± 0.6 < 0.05 28.2 ± 1.4 26.8 ± 0.6 < 0.05
Dmean (GyRBE) 24.5 ± 1.1 23.4 ± 1.0 < 0.05 24.7 ± 1.7 23.2 ± 0.9 < 0.05 25.2 ± 1.7 23.3 ± 0.7 < 0.05 24.9 ± 0.8 23.3 ± 0.6 < 0.05
Esophagus Dmax (GyRBE) 24.2 ± 2.3 22.0 ± 4.2 < 0.05 2.0 (0.6–3.8) 8.7(8.3–9.6) < 0.05 19.8 ± 4.3 19.4 ± 4.3 0.7 0.2 (0.1–2.4) 7.9 (5.6–9.8) < 0.05
Dmean (GyRBE) 4.5 ± 1.7 7.0 ± 1.7 < 0.05 0.2 (0.1–0.4) 3.4 (2.8–3.5) < 0.05 2.9 ± 1.2 5. 7 ± 0.9 < 0.05 0 (0–0.2) 2.9 (2.5–3.0) < 0.05
Thyroid Dmax (GyRBE) 27.7 ± 1.1 27.1 ± 1.0 0.1 1.8(1.2–2.8) 0.8 (0.7–1) 0.0 26.1 ± 2.0 25.2 ± 3.9 0.4 0.6 (0.0–1.6) 0.8 (0.7–1.0) 0.9
Dmean (GyRBE) 13.5 ± 6.0 16.3 ± 4.5 0.4 0.2 (0.1–0.3) 0.5 (0.4–0.6) < 0.05 12.5 ± 2.7 14.8 ± 1.9 < 0.05 0.1 (0–0.3) 0.5 (0.4–0.6) < 0.05
  1. Mean ± SD for normally distributed data using a paired t-test; median (IQR) for nonnormally distributed data using the Wilcoxon signed-rank test