Table 1.

Parameters used for the model simulation for early stage lung cancer. The numbers in the bracket after the values are the references. All parameters except for the radiosensitivity parameters are the same as those used in Jeong et al. [22].

Parameters		Values
Tumor parameters
Tumor cell density (⍴t)		106 mm−3 [26]
Tumor volume (Vt)		30 cc
Stem cell fraction (fs)		0.01 [27]
Cell cycle time (Tc)		2 days [28]
Compartment parameters
Growth fraction (GF)		0.25 [29]
Tumor doubling time (TD)		100 days [30]
Cell loss half-time in H (T1/2,loss)		2 days [31]
Survival rate of progeny after mitosis (km)		0.2 [22]
Lysis half-time (T1/2,lysis)		3 days [22]
Cell cycle parameters
Fraction of cells in P-compartment (fP)		50%a
G1-phase in P (fPG1)		28% [32]
S-phase in P (fPs)		12% [32]
G2/M-phase in P (fPG2/M)		10% [32]
Fraction of cell in I-compartment (fI)		27%a
Fraction of cell in H-compartment (fH)		23%a
Radiosensitivity parameters	Photon RT	CIRT
Ratio of alpha of G1- to S-phase (αG1/αS)	2b	1c
Ratio of alpha of G2/M- to S-phase (αG2/M/αS)	3b	1c
Reference radiosensitivity at 2 Gy/fx (α)	0.305 Gy−1 [22]	1.12d Gy−1
Alpha-beta ratio (α/β)	2.8 Gy [22]	23.9d Gy
OER of I-compartment at 2 Gy/fx (OERI)	1.7 [22]	1.08d
OER of H-compartment at 2 Gy/fx (OERH)	1.37 [33]	1.01d

^aEstimated from GF and T_D in the model.

^bAssumed parameters based on radiosensitivity analysis of synchronized cell population[34,35].

^cThe cell cycle effect is ignored for CIRT as the cell-cycle radiosensitivity variations are negligible for the high LET heavy ion[10,11].

^dThe best-fit parameter values found from the model parameter fitting.