Purpose-To evaluate four planning techniques for stereotactic body radiation therapy (SBRT) in lung tumors.Methods and Materials-Four SBRT plans were performed for 12 patients with stage I/II nonsmall-cell lung cancer under the following conditions: (1) conventional margins on free-breathing CT (plan 1), (2) generation of an internal target volume (ITV) using 4DCT with beam delivery under free-breathing conditions (plan 2), (3) gating at end-exhale (plan 3), and (4) gating at end-inhale (plan 4). Planning was performed following the RTOG 0236 protocol with a prescription dose of 54Gy (3 fractions). For each plan 4D dose was calculated using deformable image registration.Results-There was no significant difference in tumor dose delivered by the 4 plans. However, compared with plan 1, plans 2-4 reduced total lung BED by 1.9±1.2Gy, 3.1±1.6Gy and 3.5±2.1Gy, reduced mean lung dose by 0.8±0.5Gy, 1.5±0.8Gy, and 1.6±1.0Gy, reduced V20 by 1.5±1.0%, 2.7 ±1.4%, and 2.8±1.8% respectively with p<0.01. Compared with plan 2, plans 3-4 reduced lung BED by 1.2±1.0Gy and 1.6±1.5Gy, reduced mean lung dose by 0.6±0.5Gy and 0.8±0.7Gy, reduced V20 by 1.2±1.1% and 1.3±1.5% respectively with p<0.01. The differences in lung BED, mean dose and V20 of plan 4 compared with plan 3 are insignificant.Conclusions-Tumor dose coverage was statistically insignificant between all plans. However, compared with plan 1, plans 2-4 significantly reduced lung doses. Compared with plan 2, plan 3-4 also reduced lung toxicity. The difference in lung doses between plan 3 and plan 4 was not significant.