Document Type : Original Article

Authors

1 Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran

2 Medical Physics Department, Medical School, Tabriz University of Medical Sciences, Tabriz, Iran

3 Radiation Oncology Department, Imam Hospital, Tabriz, Iran

4 Radiation Oncology Department, Tabriz International Hospital, Tabriz, Iran

5 Vocational School of Health Services, Üsküdar University, Istanbul, Turkey

Abstract

Purpose: In the current study, using different radiobiological models, tumor control probability (TCP) and normal tissue complication probability (NTCP) of radiotherapy plans were calculated for three-dimensional conformal radiation therapy (3D-CRT) and intensity modulated radiation therapy (IMRT) of prostate cancer.
Methods and Materials: 10 prostate plans were randomly selected among patients undergoing radiation therapy of prostate cancer. For each patient, 3D-CRT and IMRT plans were designed to deliver, on average 76 Gy and 82 Gy to planning target volume, respectively. Using different radiobiological models including Poisson, equivalent uniform dose (EUD) and Lyman-Kutcher-Burman (LKB), TCP and NTCP were calculated for prostate and critical organs including bladder, rectum and femoral heads.
Results: IMRT plans provided significantly lower NTCP for bladder, rectum and femoral heads using LKB and EUD models (p-value <0.05). The EUD-calculated TCP for prostate cancer revealed no considerable improvement for IMRT plans relative to 3D-CRT plans. However, the TCPs calculated by Poisson model were dependent on α/β, and higher TCP for IMRT relative to 3D-CRT was seen for α/β higher than 5.
Conclusion: It can be concluded that IMRT plans were superior to 3D-CRT plans in terms of estimated NTCP for studied critical organs. On the other hand, different mathematical models provided different quantitative outcome for TCP of prostate cancer plans. More clinical studies are suggested to confirm the accuracy of studied radiobiological models.

Keywords

  1. Jensen I, Carl J, Lund B, Larsen EH, Nielsen J. Radiobiological impact of reduced margins and treatment technique for prostate cancer in terms of tumor control probability (TCP) and normal tissue complication probability (NTCP). Med Dosim. 2011;36:130-7. doi.org/10.1016/j.meddos.2010.02.004. PubMed PMID: 20488692.
  2. Koontz BF, Das S, Temple K, Bynum S, Catalano S, Koontz JI, et al. Dosimetric and radiobiologic comparison of 3D conformal versus intensity modulated planning techniques for prostate bed radiotherapy. Med Dosim. 2009;34:256-60. doi.org/10.1016/j.meddos.2008.10.005. PubMed PMID: 19647638.
  3. Luxton G, Hancock SL, Boyer AL. Dosimetry and radiobiologic model comparison of IMRT and 3D conformal radiotherapy in treatment of carcinoma of the prostate. Int J Radiat Oncol Biol Phys. 2004;59:267-84. doi.org/10.1016/j.ijrobp.2004.01.024. PubMed PMID: 15093924.
  4. Nahum AE, Uzan J. (Radio)biological optimization of external-beam radiotherapy. Comput Math Methods Med. 2012;2012:329214. PubMed PMID: 23251227. PubMed PMCID: 3508750.
  5. Rana S, Cheng C. Radiobiological impact of planning techniques for prostate cancer in terms of tumor control probability and normal tissue complication probability. Ann Med Health Sci Res. 2014;4:167-72. doi.org/10.4103/2141-9248.129023. PubMed PMID: 24761232. PubMed PMCID: 3991934.
  6. Niemierko A, Goitein M. Calculation of normal tissue complication probability and dose-volume histogram reduction schemes for tissues with a critical element architecture. Radiother Oncol. 1991;20:166-76. doi.org/10.1016/0167-8140(91)90093-V. PubMed PMID: 1852908.
  7. Stavreva N, Niemierko A, Stavrev P, Goitein M. Modelling the dose-volume response of the spinal cord, based on the idea of damage to contiguous functional subunits. Int J Radiat Biol. 2001;77:695-702. doi.org/10.1080/09553000110047555. PubMed PMID: 11403709.
  8. Warkentin B, Stavrev P, Stavreva N, Field C, Fallone BG. A TCP-NTCP estimation module using DVHs and known radiobiological models and parameter sets. J Appl Clin Med Phys. 2004;5:50-63. doi.org/10.1120/jacmp.v5i1.1970. PubMed PMID: 15753933.
  9. Ahmad S, Vogds BJ, McKenna F, Vlachaki MT. Tumor control probability (TCP) in prostate cancer: role of radiobiological parameters and radiation dose escalation. J Xray Sci Technol. 2009;17:347-54. PubMed PMID: 19923690.
  10. Krupa P, Ticha H, Kazda T, Dymackova R, Zitterbartova J, Odlozilikova A, et al. Early toxicity of hypofractionated radiotherapy for prostate cancer. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub. 2016;160:435-41. doi.org/10.5507/bp.2016.008. PubMed PMID: 26948031.
  11. Cambria R, Jereczek-Fossa BA, Cattani F, Garibaldi C, Zerini D, Fodor C, et al. Evaluation of late rectal toxicity after conformal radiotherapy for prostate cancer: a comparison between dose-volume constraints and NTCP use. Strahlenther Onkol. 2009;185:384-9. doi.org/10.1007/s00066-009-1933-8. PubMed PMID: 19506822.
  12. Deb P, Fielding A. Radiobiological model comparison of 3D conformal radiotherapy and IMRT plans for the treatment of prostate cancer. Australas Phys Eng Sci Med. 2009;32:51-61. doi.org/10.1007/BF03178629. PubMed PMID: 19623855.
  13. Rancati T, Fiorino C, Gagliardi G, Cattaneo GM, Sanguineti G, Borca VC, et al. Fitting late rectal bleeding data using different NTCP models: results from an Italian multi-centric study (AIROPROS0101). Radiother Oncol. 2004;73:21-32. doi.org/10.1016/j.radonc.2004.08.013. PubMed PMID: 15465142.
  14. Warren S, Partridge M, Carrington R, Hurt C, Crosby T, Hawkins MA. Radiobiological determination of dose escalation and normal tissue toxicity in definitive chemoradiation therapy for esophageal cancer. Int J Radiat Oncol Biol Phys. 2014;90:423-9. doi.org/10.1016/j.ijrobp.2014.06.028. PubMed PMID: 25304796. PubMed PMCID: 4165721.
  15. Mesbahi A, Zergoug I. Dose Calculations for Lung Inhomogeneity in High-Energy Photon Beams and Small Beamlets: A Comparison between XiO and TiGRT Treatment Planning Systems and MCNPX Monte Carlo Code. Iranian Journal of Medical Physics. 2015;12:167-77.
  16. Mesbahi A, Dadgar H. Dose calculations accuracy of TiGRT treatment planning system for small IMRT beamlets in heterogeneous lung phantom. International Journal of Radiation Research. 2015;13:345-54.
  17. Sanchez-Nieto B, Nahum AE. BIOPLAN: software for the biological evaluation of. Radiotherapy treatment plans. Med Dosim. 2000;25:71-6. doi.org/10.1016/S0958-3947(00)00031-5. PubMed PMID: 10856684.
  18. Burman C, Kutcher GJ, Emami B, Goitein M. Fitting of normal tissue tolerance data to an analytic function. Int J Radiat Oncol Biol Phys. 1991;21:123-35. doi.org/10.1016/0360-3016(91)90172-Z. PubMed PMID: 2032883.
  19. Lyman JT. Complication probability as assessed from dose-volume histograms. Radiat Res Suppl. 1985;8:S13-9. doi.org/10.2307/3583506. PubMed PMID: 3867079.
  20. Gay HA, Niemierko A. A free program for calculating EUD-based NTCP and TCP in external beam radiotherapy. Phys Med. 2007;23:115-25. doi.org/10.1016/j.ejmp.2007.07.001. PubMed PMID: 17825595.
  21. Carlone M, Wilkins D, Nyiri B, Raaphorst P. Comparison of alpha/beta estimates from homogeneous (individual) and heterogeneous (population) tumor control models for early stage prostate cancer. Med Phys. 2003;30:2832-48. doi.org/10.1118/1.1612946. PubMed PMID: 14596319.
  22. Valdagni R, Italia C, Montanaro P, Lanceni A, Lattuada P, Magnani T, et al. Is the alpha-beta ratio of prostate cancer really low? A prospective, non-randomized trial comparing standard and hyperfractionated conformal radiation therapy. Radiother Oncol. 2005;75:74-82. doi.org/10.1016/j.radonc.2004.12.019. PubMed PMID: 15878104.
  23. Hancock S, Luxton G, Chen Y, Xing L, Boyer A. Intensity modulated radiotherapy for localized or regional treatment of prostatic cancer: Clinical implementation and improvement in acute tolerance. International Journal of Radiation Oncology* Biology* Physics. 2000;48:252-3. doi.org/10.1016/S0360-3016(00)80301-6.