Development of a risk prediction model for radiation dermatitis following proton radiotherapy in head and neck cancer using ensemble machine learning

Table 2 Dosimetric features of patients

Variable	< Grade 2 RD n = 26		≥ Grade 2 RD n = 31		p-value
Variable	Mean	Range	Mean	Range
Skin 3 mm
V₄₀ (ml)	58.26	23.26–116.06	65.62	23.44–155.41	0.040
V₅₀	21.41	0.93–77.16	26.48	3.81–65.99	0.038
V₆₀	1.49	0–9.12	4.79	0–30.17	0.021
V₇₀	0.03	0–0.53	0.67	0–10.26	0.294
D₁₀ (Gy)	52.06	44.53–59.85	54.78	45.84–70.11	0.025
D₃₀	46.97	38.17–57.00	48.34	37.96–60.08	0.078
D₅₀	42.00	33.24–54.19	42.95	32.85–52.41	0.068
D₇₀	36.13	24.59–51.51	37.50	27.06–49.53	0.027
D₁₀₀	28.44	17.76–44.06	30.20	21.48–46.44	0.020
Skin 5 mm
V₄₀ (ml)	104.61	52–199.16	116.08	46.47–237.43	0.035
V₅₀	45.80	6.12–136.03	54.05	10.97–115.17	0.035
V₆₀	4.37	0–25.49	10.55	0.15–47.61	0.008
V₇₀	0.21	0–1.86	1.50	0–17.89	0.167
D₁₀ (Gy)	55.74	48.60–64.13	58.69	50.38–71.76	0.014
D₃₀	51.43	44.01–59.63	53.43	44.15–65.53	0.034
D₅₀	48.53	40.33–58.03	49.93	39.30–59.28	0.062
D₇₀	45.66	37.10–56.31	46.73	35.52–54.29	0.081
D₁₀₀	40.49	29.69–53.75	41.87	31.85–51.12	0.037

Abbreviations RD: Radiation dermatitis; Vx: Volume receiving x Gy dose; Dx: Dose received by x cc volume

ISSN: 1748-717X