Table 3.
Summary and comparison of the dosimetric parameters of peripherally located tumors (60 CGE/4 fx = 9).
| OARs | PBT | 3D-CRT | IMRT | VMAT | p-Value | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Median | Range | Median | Range | Median | Range | Median | Range | PBT vs.3D-CRT | PBT vs.IMRT | PBT vs.VMAT | ||
| Total lung (n = 9) | ||||||||||||
| V5 (%) | 12.59 | 6.0–17.7 | 17.26 | 10.2–24.6 | 17.83 | 10.2–24.1 | 17.49 | 10.2–22.8 | 0.004 | 0.004 | 0.004 | |
| V10 (%) | 10.28 | 5.0–15.0 | 13.41 | 7.9–19.9 | 13.48 | 8.0–19.2 | 12.28 | 6.4–15.6 | 0.008 | 0.008 | 0.039 | |
| V15 (%) | 8.37 | 4.1–12.4 | 10.32 | 6.5–16.3 | 9.87 | 5.9–15.3 | 8.54 | 5.0–11.5 | 0.039 | 0.055 | 0.820 | |
| V20 (%) | 6.36 | 3.3–10.9 | 7.19 | 4.4–11.3 | 6.35 | 4.0–10.5 | 5.79 | 3.6–8.6 | 0.098 | 0.426 | 0.098 | |
| V30 (%) | 3.88 | 2.1–8.1 | 3.6 | 2.1–6.0 | 3.46 | 2.1–5.6 | 3.17 | 2.0–5.3 | 0.098 | 0.074 | 0.004 | |
| V40 (%) | 2.49 | 1.3–5.7 | 2.16 | 1.2–3.4 | 2.18 | 1.1–3.2 | 1.99 | 1.1–3.1 | 0.009 | 0.019 | 0.004 | |
| Mean dose (Gy) | 3.32 | 1.9–5.2 | 4.57 | 2.9–6.4 | 4.68 | 2.8–6.2 | 4.23 | 2.6–5.5 | 0.004 | 0.004 | 0.004 | |
| Heart (n = 9) | ||||||||||||
| V5 (%) | 0 | 0–0.9 | 6.62 | 0–17.2 | 8.82 | 0–23.2 | 11.43 | 0–24.8 | 0.036 | 0.036 | 0.036 | |
| V10 (%) | 0 | 0–0.4 | 0.03 | 0–2.4 | 0.27 | 0–4.5 | 1.1 | 0–5.0 | 0.036 | 0.036 | 0.036 | |
| V15 (%) | 0 | 0–0.1 | 0 | 0 | 0 | 0–0.2 | 0 | 0–0.6 | 1 | 1 | 0.100 | |
| V20 (%) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0–0.1 | 1 | 1 | 0.371 | |
| V30 (%) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | NA | NA | NA | |
| V40 (%) | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | NA | NA | NA | |
| Mean dose (Gy) | 0 | 0–0.1 | 1.34 | 0.2–3.0 | 1.48 | 0.1–3.4 | 1.95 | 0.2–3.3 | 0.009 | 0.004 | 0.004 | |
| Dmax (Gy) | 0.03 | 0–18.9 | 10.88 | 0.6–16.1 | 12.46 | 0.6–17.4 | 13.5 | 0.5–23.9 | 0.129 | 0.129 | 0.004 | |
| Proximal bronchial tree (n = 5) | ||||||||||||
| Dmax (Gy) | 10.35 | 0–41.0 | 17.24 | 1.0–48.6 | 22.09 | 0.9–37.3 | 20.79 | 1.0–35.0 | 0.062 | 0.187 | 0.312 | |
| D1cc (Gy) | 0.27 | 0–11.2 | 5.06 | 0.9–11.9 | 8.07 | 0.8–14.3 | 9.62 | 0.9–18.1 | 0.187 | 0.062 | 0.062 | |
| Spinal cord (n = 9) | ||||||||||||
| Dmax (Gy) | 0.01 | 0–8.5 | 10.0 | 3.6–16.7 | 9.8 | 4.5–13.0 | 11.41 | 5.8–17.8 | 0.004 | 0.004 | 0.004 | |
| Esophagus (n = 8) | ||||||||||||
| Mean dose (Gy) | 0 | 0–0.4 | 2.11 | 0.7–4.0 | 2.28 | 1.0–4.3 | 2.74 | 0.8–6.1 | 0.008 | 0.008 | 0.014 | |
| Dmax (Gy) | 0 | 0–11.1 | 8.60 | 4.1–13.7 | 7.97 | 6.4–15.6 | 11.85 | 5.8–17.4 | 0.016 | 0.016 | 0.008 | |
| Chest wall (n = 9) | ||||||||||||
| Dmax (Gy) | 44.35 | 31.0–75.9 | 39.72 | 28.9–73.0 | 41.68 | 29.1–76.3 | 44.01 | 34.4–72.8 | 0.734 | 0.652 | 0.203 | |
| D30cc (Gy) | 17.6 | 12.3–30.6 | 24.19 | 17.2–35.7 | 24.06 | 15.7–33.9 | 24.09 | 15.5–32.3 | 0.019 | 0.019 | 0.019 | |
| Skin (n = 8) | ||||||||||||
| Dmax (Gy) | 14.32 | 10.4–28.6 | 23.97 | 17.9–35.4 | 23.8 | 19.1–31.2 | 24.15 | 14.8–32.6 | 0.008 | 0.008 | 0.008 | |
OARs, organs at risk; PBT, proton beam therapy; 3D-CRT, three-dimensional conformal radiotherapy; IMRT, intensity-modulated radiotherapy; VMAT, volumetric-modulated arc therapy, CGE, cobalt gray equivalent; fx, fractions; V5–40; percentage volume of tissue receiving 5–40 Gy; Dmax, maximum dose; D1cc, the dose delivered to 1 cubic centimeter volume; D30cc, the dose delivered to 30 cubic centimeter volume.