The purpose of this study was to compare the dose-volume statistics of stereotactic body radiotherapy (SBRT) for lung cancer between planning target volume (PTV): D95 and gross tumor volume (GTV): D99 dose prescriptions using Monte Carlo (MC) calculation. Plans for 183 patients treated between October 2010 and April 2013 were generated based on four-dimensional (4D) computed tomography (CT) under free breathing. A uniform margin of 8 mm was added to the internal target volume (ITV) to generate PTV. A leaf margin of 2 mm was added to the PTV. The plans were calculated with two different dose prescription methods: 40 Gy to cover 95% of the PTV (PTV prescription) and 44 Gy to cover 99% of the GTV (GTV prescription). A 6-MV photon beam was used. A dose-volume histogram (DVH) analysis was performed for dose to the GTV using PTV and GTV dose prescriptions. For each treatment plan, we evaluated the minimum dose to 99% of the GTV (D99). The D99 of GTV was 44.5 ± 1.9 Gy and 44.0 ± 0.0 Gy for PTV and GTV prescriptions, respectively. The dose to the GTV had wide variations with PTV prescription. We recommend that GTV based dose prescription should be used to standardize dose to the tumor and to achieve highly conformal dose distributions in SBRT for lung cancer.
 Y. Nagata, J. Wulf, I. Lax, et al., “Stereotactic Radiotherapy of Primary Lung Cancer and Other Targets: Results of Consultant Meeting of the International Atomic Energy Agency,” International Journal of Radiation Oncology * Biology * Physics, Vol. 79, No. 3, 2011, pp. 660-669.
 H. Onishi, T. Araki, H. Shirato, et al., “Stereotactic Hypofractionated High-Dose Irradiation for Stage I Non-Small Cell Lung Carcinoma,” Cancer, Vol. 101, No. 7, 2004, pp. 1623-1631.
 R. Timmerman, L. Papiez, R. McGarry, et al., “Extracranial Stereotactic Radioablation: Results of a Phase I Study in Medically Inoperable Stage I Non-Small Cell Lung Cancer,” Chest, Vol. 124, No. 5, 2003, pp. 1946-1955. http://dx.doi.org/10.1378/chest.124.5.1946
 Y. Nagata, K. Takayama, Y. Matsuo, et al., “Clinical Outcomes of a Phase I/II Study of 48 Gy of Stereotactic Body Radiotherapy in 4 Fractions for Primary Lung Cancer Using a Stereotactic Body Frame,” International Journal of Radiation Oncology * Biology * Physics, Vol. 63, No. 5, 2005, pp. 1427-1431.
 L. R. Aarup, A. E. Nahum, C. Zacharatou, et al., “The Effect of Different Lung Densities on the Accuracy of Various Radiotherapy Dose Calculation Methods: Implications for Tumour Coverage,” Radiotherapy & Oncology, Vol. 91, No. 3, 2009, pp. 405-414.
 V. Panettieri, B. Wennberg, G. Gagliardi M. Ginjaume and I. Lax, “SBRT of Lung Tumours: Monte Carlo Simulation with PENELOPE of Dose Distributions Including Respiratory Motion and Comparison with Different Treatment Planning Systems,” Physics in Medicine and Biology, Vol. 52, No. 14, 2007, pp. 4265-4281.
 U. Haedinger, T. Krieger, M. Flentje and J. Wulf, “Influence of Calculation Model on Dose Distribution in Stereotactic Radiotherapy for Pulmonary Targets,” International Journal of Radiation Oncology * Biology * Physics, Vol. 61, No. 1, 2005, pp. 239-249.
 C. Kappas and J. C. Rosenwald, “Quality Control of Inhomogeneity Correction Algorithms Used in Treatment Planning Systems,” International Journal of Radiation Oncology * Biology * Physics, Vol. 32, No. 3, 1995, pp. 847-858.
 R. Oh, N. Masai, H. Shiomi and T. Inoue. “The ‘Air-Bag System’: A Novel Respiratory Monitoring Device Collaborated with RPM System,” International Journal of Radiation Oncology * Biology * Physics, Vol. 78, No. 3, 2010, pp. 824-825 (Abstract).
 M. Fippel, “Fast Monte Carlo Dose Calculation for Photon Beams Based on the VMC Electron Algorithm,” Medical Physics, Vol. 26, No. 8, 1999, pp. 1466-1475.
 M. Fippel, F. Haryanto, O. Dohm, F. Nüsslin and S. Kriesen, “A Virtual Photon Energy Fluence Model for Monte Carlo Dose Calculation,” Medical Physics, Vol. 30, No. 3, 2003, pp. 301-311.
 M. Fippel, “Efficient Particle Transport Simulation through Beam Modulating Devices for Monte Carlo Treatment Planning,” Medical Physics, Vol. 31, No. 5, 2004, pp. 1235-1242. http://dx.doi.org/10.1118/1.1710734
 I. Kawrakow, M. Fippel and K. Friedrich, “3D Electron Dose Calculation Using a Voxel Based Monte Carlo Algorithm (VMC),” Medical Physics, Vol. 23, No. 4, 1996, pp. 445-457. http://dx.doi.org/10.1118/1.597673
 H. Miura, N. Masai, R. J. Oh, H. Shiomi, J. Sasaki and T. Inoue, “Approach to Dose Prescription of the Gross Tumor Volume for Lung Cancer with Respiratory Tumor Motion,” Journal of Radiation Research, Vol. 54, No. 1, 2013, pp. 140-145. http://dx.doi.org/10.1093/jrr/rrs054
 H. Hof, J. Zgoda, S. Nill, et al., “Time- and Dose-Dependency of Radiographic Normal Tissue Changes of the Lung after Stereotactic Radiotherapy,” International Journal of Radiation Oncology * Biology * Physics, Vol. 77, No. 5, 2010, pp. 1369-1374.
 A. Takeda, T. Ohashi, E. Kunieda, et al., “Early Graphical Appearance of Radiation Pneumonitis Correlates with the Severity of Radiation Pneumonitis after Stereotactic Body Radiotherapy (SBRT) in Patients with Lung Tumors,” International Journal of Radiation Oncology * Biology * Physics, Vol. 77, No. 3, 2010, pp. 685-690.
 M. Guckenberger, J. Wilbert, T. Krieger, et al., “Four-Dimensional Treatment Planning for Stereotactic Body Radiotherapy,” International Journal of Radiation Oncology * Biology * Physics, Vol. 69, No. 1, 2007, pp. 276-285.
 P. Baumann, J. Nyman, M. Hoyer, et al., “Outcome in a Prospective Phase II Trial of Medically Inoperable Stage I Non-Small Cell Lung Cancer Patients Treated with Stereotactic Body Radiotherapy,” Journal of Clinical Oncology, Vol. 27, No. 20, 2009, pp. 3290-3296.
 S. W. Lee, E. K. Choi, H. J. Park, et al., “Stereotactic Body Frame Based Fractionated Radiosurgery on Consecutive Days for Primary or Metastatic Tumors in the Lung,” Lung Cancer, Vol. 40, No. 3, 2003, pp. 309-315.
 I. Lax, “Target Dose versus Extra-Target Dose in Stereotactic Radiosurgery,” Acta Oncologica, Vol. 32, No. 4, 1993, pp. 453-457.
 N. Pettersson, J. Nyman and K. A. Johansson, “Radiation-Induced Rib Fracture after Hypofractionated Stereotactic Body Radiation Therapy of Non-Small Cell Lung Cancer: A Dose- and Volume-Response Analysis,” Radiotherapy & Oncology, Vol. 91, No. 3, 2009, pp. 360-368.
 S. S. Kim, S. Y. Song, J. Kwak, et al., “Clinical Prognostic Factors and Grading System for Rib Fracture Following Stereotactic Body Radiation Therapy (SBRT) in Patients with Peripheral Lung Tumors,” Lung Cancer, Vol. 79, No. 2, 2013, pp. 161-166.
 V. Gregoire, T. R. Mackie, W. D. Neve, et al., “Prescribing Recording and Reporting Photon-Beam Intensity-Modulated Radiation Therapy (IMRT),” Journal of the ICRU, Vol. 10, No. 1, 2010, pp. 1-112.