Dosimetric Comparative Study between Single and Dual Isocenter Stereotactic Body Radiotherapy Plans in Treatment of Multiple Lesions Non-Small Cell Lung Cancer Patients

Document Type : Original Paper


1 Physics Department, Faculty of Science, Zagazig University, Zagazig, Egypt.

2 Clinical Oncology and Nuclear Medicine Department, Faculty of Medicine, El-Azhar University, Cairo, Egypt

3 Clinical Oncology and Nuclear Medicine Department, Faculty of Medicine, ZagazigUniversity, Zagazig, Egypt.

4 Radiation Oncology Department, International Medical Center (IMC), Egypt.

5 Clinical Oncology and Nuclear Medicine department, Zagazig University Hospitals, Egypt.


Introduction: stereotactic body radiotherapy (SBRT) is the most proper treatment for multi lesions non-small cell lung cancer (NSCLC) for enhanced good coverage and minimizing dose to organs at risk (OARs). This study aims to compare single and dual isocenter SBRT plans and discuss which technique we can use in multi lesions NSCLC.
Material and Methods: Ten patients with multi targets NSCLC underwent two different SBRT treatment planning techniques including single isocenter and dual isocenter. We quantitatively assessed plans qualities by dose-volume metrics. Conformity index (CI), Confirmation Number (CN), heterogeneity index (HI), gradient distance (GD), Gradient index (GI), and maximum percentage dose at 2cm all around PTV ( ) were gathered, tallied, and statistically examined. OARs were evaluated and the dose to the normal lung was evaluated using V5, V10, V20, and mean lung dose (MLD).
Results: There is an insignificant difference between single and dual isocenter plans in CI, CN, HI, GD, GI, and dose spillage where the mean distance between two lesions was 5.50 ± 1.50 cm, and the mean total volume of the planning target volume (PTV) was 42.60±21.33cc. For single and dual isocenter plans, the median MLD was 4.5(2-16)Gy and 4 (2-16)Gy respectively (p=0.25).
Conclusion: Plan quality of single isocenter was equal to dual isocenter for SBRT treatment of multi lung lesions with maximum distances between them was 10 cm.  Dual isocenter took time during setup and matching for cone beam computed tomography (CBCT).


Main Subjects

  1. Sung H, Ferlay J, Siegel RL, Laversanne M, Soerjomataram I, Jemal A, et al. Global cancer statistics 2020: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin.2021;71(3):209-49.
  2. Onishi H, Shirato H, Nagata Y, Hiraoka M, Fujino M, Gomi K, et al. Stereotactic body radiotherapy (SBRT) for operable stage I non-small-cell lung cancer: can SBRT be comparable to surgery? Int J Radiat Oncol Biol Phys. 2011;81(5):1352-8.
  3. Zhang B, Zhu F, Ma X, Tian Y, Cao D, Luo S, et al. matched-pair comparisons of stereotactic body radiotherapy (SBRT) versus surgery for the treatment of early-stage non-small-cell lung cancer: a systematic review and meta-analysis. Radiother Oncol. 2014;112(2):250-5.
  4. Potters L, Kavanagh B, Galvin JM, Hevezi JM, Janjan NA, Larson DA, et al; American Society for Therapeutic Radiology and Oncology; American College of Radiology. American Society for Therapeutic Radiology and Oncology (ASTRO) and American College of Radiology (ACR) practice guidelines for the performance of stereotactic body radiation therapy. Int J Radiat Oncol Biol Phys. 2010;76(2):326-32.
  5. Moreno AC, Fellman B, Hobbs B0P, Liao Z, Gomez DR, Chen A, et al. Biologically Effective Dose in Stereotactic Body Radiotherapy and Survival for Patients with Early-Stage NSCLC. Journal of Thoracic Oncology.2020; 15(1):101-9.
  6. Timmerman R, Paulus R, Galvin J, Michalski J, Straube W, Bradley J, et al. Stereotactic body radiation therapy for inoperable early-stage lung cancer. JAMA. 2010; 303(11):1070-6.
  7. Rusthoven KE, Kavanagh BD, Burri SH, Chen C, Cardenes H, Chidel MA, et al. Multi-institutional phase I/II trial of stereotactic body radiation therapy for lung metastases. J Clin Oncol. 2009;27(10):1579-84.
  8. Jiang X, Li T, Liu Y, Zhou L, Xu Y, Zhou X, et al. Planning analysis for locally advanced lung cancer: dosimetric and efficiency comparisons between intensity-modulated radiotherapy (IMRT), single-arc/partial-arc volumetric modulated arc therapy (SA/PA-VMAT). Radiat Oncol. 2011;6(1):1-7.
  9. Zhang J, Lu J, Wu L, Hong D, Ma C, Peng X, et al. A dosimetric and treatment efficiency evaluation of stereotactic body radiation therapy for peripheral lung cancer using flattening filter-free beams. Oncotarget. 2016;7(45):73792-9.
  10. Navarria P, Ascolese AM, Mancosu P, Alongi F, Clerici E, Tozzi A, et al. Volumetric modulated arc therapy with flattening filter free (FFF) beams for stereotactic body radiation therapy (SBRT) in patients with medically inoperable early-stage non-small cell lung cancer (NSCLC). Radiother Oncol. 2013;107(3):414-8.
  11. Yu S, Xu H, Sinclair A, Zhang X, Langner U, Mak K. Dosimetric and planning efficiency comparison for lung SBRT: CyberKnife vs VMAT vs knowledge-based VMAT. Med Dosim. 2020;45(4):346-51.
  12. Chan MK, Kwong DL, Law GM, Tam E, Tong A, Lee V, et al. Dosimetric evaluation of four-dimensional dose distributions of CyberKnife and volumetric-modulated arc radiotherapy in stereotactic body lung radiotherapy. J Appl Clin Med Phys. 2013;14(4):4229.
  13. Brandner ED, Chetty IJ, Giaddui TG, Xiao Y, Huq MS. Motion management strategies and technical issues associated with stereotactic body radiotherapy of thoracic and upper abdominal tumors: A review from NRG oncology. Medical physics.2017; 44(6): 2595–
  14. Rahn DA, Thakur S, Makani S, Sandhu A. Stereotactic body radiation therapy (SBRT) for multiple primary lung cancers (MPLC): a review and case series. Journal of radiosurgery and SBRT. 2013;2(2): 135–
  15. Al-Hallaq HA, Chmura S, Salama JK, Winter KA, Robinson CG, Pisansky TM, et al. Rationale of technical requirements for NRG-BR001: The first NCI-sponsored trial of SBRT for the treatment of multiple metastases. Pract Radiat Oncol. 2016;6(6):291-8.
  16. Pokhrel D, Sanford L, Halfman M, Molloy J. Potential reduction of lung dose via VMAT with jaw tracking in the treatment of single-isocenter/two-lesion lung SBRT. J Appl Clin Med Phys. 2019;20(5):55-63.
  17. Pokhrel D, Sanford L, Larkin S, Dhanireddy B, Bernard ME, Randall ME, et al. On the use of single‐isocenter VMAT plans for SBRT treatment of synchronous multiple lung lesions: Plan quality, treatment efficiency, and early clinical outcomes. Journal of Applied Clinical Medical Physics. 2020; 21:160 –
  18. Sanford L, Molloy J, Kumar S, Randall M, McGarry R, Pokhrel D. Evaluation of plan quality and treatment efficiency for single-isocenter/two-lesion lung stereotactic body radiation therapy. Journal of applied clinical medical physics.2019; 20(1): 118–
  19. Quan K, Xu KM, Lalonde R, Horne ZD, Bernard ME, McCoy C, et al. Treatment Plan Technique and Quality for Single-Isocenter Stereotactic Ablative Radiotherapy of Multiple Lung Lesions with Volumetric-Modulated Arc Therapy or Intensity-Modulated Radiosurgery. Front Oncol. 2015; 5:213.
  20. Gulam M, Gopal A, Wen NW, Gordon JJ, Levin KJ, Chetty IJ, et al. Single Isocenter Lung SBRT for Multiple PTV Lesions. International Journal of Radiation Oncology Biology Physics.2014; 90:S910–
  21. Feuvret L, Noël G, Mazeron JJ, Bey P. Conformity index: a review. Int J Radiat Oncol Biol Phys. 2006;64(2):333-42.
  22. Paddick I. A simple scoring ratio to index the conformity of radiosurgical treatment plans. Technical note. J Neurosurg. 2000;93 Suppl 3:219-22
  23. . Shaw E, Kline R, Gillin M, Souhami L, Hirschfeld A, Dinapoli R, et al. Radiation Therapy Oncology Group: Radiosurgery quality assurance guidelines. Int J Radiat Oncol Biol Phys. 1993;27:1231–9
  24. Eclipse Photon and Electron 15.5 Reference Guide. Varian Med Syst. 2017;1–
  25. Paddick I, Lippitz B. A simple dose gradient measurement tool to complement the conformity index. J Neurosurg. 2006;105 Suppl:194-201.
  26. Hoffman D, Dragojević I, Hoisak J, Hoopes D, Manger R. Lung Stereotactic Body Radiation Therapy (SBRT) dose gradient and PTV volume: a retrospective multi-center analysis. Radiat Oncol. 2019;14(1):162.
  27. De Rose, D. Franceschini, G. Reggiori, A. Stravato, P. Navarria, et al. Organs at risk in lung SBRT, Physica Medica, 2017;44 :131-138.
  28. Liu H, Ye J, Kim JJ, Deng J, Kaur MS, Chen ZJ. Dosimetric comparison of two arc-based stereotactic body radiotherapy techniques for early-stage lung cancer. Med Dosim. 2015; 40(1):76–
  29. Sanford L, Pokhrel D. Improving treatment efficiency via photon optimizer (PO) MLC algorithm for synchronous single-isocenter/multiple-lesions VMAT lung SBRT. J Appl Clin Med Phys. 2019;20(10):201-7.