Table 4.

Two simulation models comparison: MCNP5 model with air cavity filled with air, and TPS model with air cavity filled with water.

34 cc	Air Cavity Radius
		0.25 cm	0.50 cm	1.00 cm	1.44 cm
	MCNP5 ${(\mathrm{D}}_{\text{sur}-\text{ac}})$	603.3 cGy	492.6 cGy	346.5 cGy	266.1 cGy
Air Cavity Surface	TPS (${\mathrm{D}}_{\text{sur}-\text{ac}}^{,}$)	598.3 cGy	483.0 cGy	333.4 cGy	252.6 cGy
	MCNP5 ${(\mathrm{D}}_{\text{PVT}-\text{ac}})$	286.8 cGy	251.7 cGy	196.6 cGy	161.3 cGy
Air Cavity PTV Point	TPS (${\mathrm{D}}_{\text{sur}-\text{ac}}^{,}$)	281.7cGy	243.8 cGy	184.7 cGy	149.9 cGy
70 cc (S)	Air Cavity Radius
		0.50 cm	1.00 cm	1.50 cm	1.66 cm
	MCNP5 ${(\mathrm{D}}_{\text{sur}-\text{ac}})$	475.3 cGy	354.6 cGy	274.7 cGy	256.7 cGy
Air Cavity Surface	TPS (${\mathrm{D}}_{\text{sur}-\text{ac}}^{,}$)	467.2 cGy	341.7 cGy	259.1 cGy	241.1 cGy
	MCNP5 ${(\mathrm{D}}_{\text{PVT}-\text{ac}})$	267.2 cGy	217.3 cGy	179.9 cGy	169.0 cGy
Air Cavity PTV Point	TPS (${\mathrm{D}}_{\text{sur}-\text{ac}}^{,}$)	260.1 cGy	205.4 cGy	165.9 cGy	155.0 cGy
70 cc (L)	Air Cavity Radius
		0.50 cm	1.00 cm	1.50 cm	1.62 cm
	MCNP5 ${(\mathrm{D}}_{\text{sur}-\text{ac}})$	470.2 cGy	347.5 cGy	267.2 cGy	255.0 cGy
Air Cavity Surface	TPS (${\mathrm{D}}_{\text{sur}-\text{ac}}^{,}$)	458.7 cGy	333.9 cGy	252.6 cGy	239.7 cGy
Air Cavity PTV Point	MCNP5 ${(\mathrm{D}}_{\text{PVT}-\text{ac}})$	262.5 cGy	209.1 cGy	173.1 cGy	165.6 cGy
	TPS (${\mathrm{D}}_{\text{sur}-\text{ac}}^{,}$)	254.3 cGy	197.5 cGy	160.1 cGy	152.0 cGy
125 cc	Air Cavity Radius
		0.50 cm	1.00 cm	1.50 cm	2.00 cm
	MCNP5 ${(\mathrm{D}}_{\text{sur}-\text{ac}})$	453.9 cGy	351.6 cGy	280.8 cGy	230.5 cGy
Air Cavity Surface	TPS (${\mathrm{D}}_{\text{sur}-\text{ac}}^{,}$)	445.7 cGy	337.3 cGy	264.5 cGy	212.8 cGy
	MCNP5 ${(\mathrm{D}}_{\text{PVT}-\text{ac}})$	272.0 cGy	225.1 cGy	189.7 cGy	161.2 cGy
Air Cavity PTV Point	TPS (${\mathrm{D}}_{\text{sur}-\text{ac}}^{,}$)	263.8 cGy	212.5 cGy	174.8 cGy	145.5 cGy