Table 2.

Mean critical total lung volumes received on the photon SBRT, PSPT, and IMPT plans

Critical Lung Volumes	Photon SBRT	PSPT	p*	IMPT	p†	p‡
Mean total lung dose, Gy (SE)	5.4 (0.5)	3.5 (0.4)	< 0.001	2.8 (0.3)	< 0.001	< 0.001
Mean total lung V5, % (SE)	22.9 (2.1)	11.4 (1.1)	< 0.001	10.0 (1.1)	< 0.001	0.001
Mean total lung V10, % (SE)	15.2 (1.5)	10.3 (1.0)	< 0.001	8.2 (1.0)	< 0.001	< 0.001
Mean total lung V20, % (SE)	8.7 (1.1)	6.7 (0.8)	0.039	5.5 (0.6)	0.004	< 0.001

Abbreviations: IMPT = intensity-modulated proton therapy; PSPT = passive-scattering proton therapy; SBRT = stereotactic body radiation therapy; SE = standard error; V5 = volume of total lung receiving 5 Gy; V10 = volume of total lung receiving 10 Gy; V20 = volume of total lung receiving 20 Gy.

^*Photon SBRT vs PSPT

^†Photon SBRT vs IMPT

^‡PSPT vs IMPT