Comparison of gamma index based on dosimetric error and clinically relevant dose–volume index based on three-dimensional dose prediction in breast intensity-modulated radiation therapy

Table 2 Parameters for calculating TCP/NTCP

Structure	Endpoint	Tissue-specific parameter	TCD₅₀/D₅₀ (Gy)	γ₅₀/γ	s	Ref.
PTV	Local control	−7.2	30.89	1.3		[37, 38]
Lung	Pneumonitis	1	26.16	0.973	0.012	[28]
Heart	Late cardiac mortality	3	52.3	1.28	1	[39]

TCD₅₀: dose required for 50% probability of tumor control, D₅₀: dose required for 50% probability of normal tissue complication, γ₅₀: slope of normalized tumor dose-response curve at TCD₅₀, γ: slope of maxixum normalized normal tissue dose-response curve, s: relative seriality parameter