Organs-at-risk dose constraints in head and neck intensity-modulated radiation therapy using a dataset from a multi-institutional clinical trial (JCOG1015A1)

Table 4 The 3- and 5-year cumulative incidence rate of late toxicities by dose metrics

End point	Normal tissue	Dose metric	Number	3 year (95% CI)	5 year (95% CI)	p-value
Myelitis G1	Brainstem	D1cc ≥ 55.8 Gy	15	27% (8–50)	27% (8–50)	0.010
		D1cc < 55.8 Gy	59	3% (0–10)	5% (1–13)
CNS necrosis ≥ G1	Brain	D1cc ≥ 72.1 Gy	17	0% (N/A)	24% (3–56)	0.0056
		D1cc < 72.1 Gy	57	0% (N/A)	0% (N/A)
Optic nerve disorder G2	Optic nerve	Dmax ≥ 53.3 Gy	13	0% (N/A)	8% (0–32)	0.051
		Dmax < 53.3 Gy	61	0% (N/A)	0% (N/A)
Optic nerve disorder G2	Eye ball	Dmax ≥ 36.6 Gy	9	0% (N/A)	13% (0–43)	0.012
		Dmax < 36.6 Gy	65	0% (N/A)	0% (N/A)
Dysphagia ≥ G2	PCM	Dmean ≥ 41.2 Gy	48	6% (2–16)	14% (6–26)	0.21
		Dmean < 41.2 Gy	26	0% (N/A)	4% (0–17)
Hearing impaired ≥ G2	Inner ear (contralateral)	Dmean ≥ 37.6 Gy	39	21% (10–34)	35% (17–53)	0.062
		Dmean < 37.6 Gy	35	9% (2–21)	17% (6–33)
Hearing impaired ≥ G2	Inner ear (ipsilateral)	Dmean ≥ 44.0 Gy	27	19% (7–40)	42% (20–63)	0.041
		Dmean < 44.0 Gy	45	11% (4–22)	18% (7–32)
Middle ear inflammation ≥ G2	Inner ear (ipsilateral)	Dmean ≥ 51.5 Gy	18	50% (22–73)	73% (34–92)	0.0037
		Dmean < 51.5 Gy	54	19% (10–30)	25% (15–38)
Hypothyroidism ≥ G1	Thyroid	Dmean ≥ 45.6 Gy	49	16% (8–30)	38% (24–53)	0.15
		Dmean < 45.6 Gy	21	8% (1–23)	22% (6–46)

ISSN: 1748-717X