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Trade-off between the conflicting planning goals in correlation with patient’s anatomical parameters for intensity-modulated radiotherapy of prostate cancer patients

Published online by Cambridge University Press:  11 April 2019

Amin Banaei ,
Bijan Hashemi ,
Mohsen Bakhshandeh  and
Bahram Mofid
Amin Banaei
Affiliation:
Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
Bijan Hashemi*
Affiliation:
Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
Mohsen Bakhshandeh
Affiliation:
Department of Radiology Technology, Faculty of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Bahram Mofid
Affiliation:
Department of Radiation Oncology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
*
Author for correspondence: Bijan Hashemi, Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Al-Ahmad and Chamran Cross, Tehran 1411713116, Iran. Tel: +98-21-82883892. Fax: +98-21-88006544. E-mail: bhashemi@modares.ac.ir
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Abstract

Aim

To quantify the relationship between the planning target volume (PTV) dose homogeneity and organs at risk (OARs) sparing in correlation with anatomical parameters in prostate intensity-modulated radiotherapy (IMRT).

Materials and methods

Nine IMRT plans with various target dose constraints’ priorities were created for 15 prostate cancer patients. Selected PTV and OARs parameters were calculated for the patients. A trade-off was assessed between homogeneity index (HI) and OAR sparing. Several anatomical parameters were evaluated to investigate their effects on the OAR sparing and HI.

Results

Inverse exponential relationships were found between the OAR sparing and HI (average R2 of 0·983 and 0·994 for bladder and rectum, respectively). Decreasing the priority led to more OARs sparing (normal tissue complication probability reduction: 97·6 and 74·5%; mean dose reduction: 16·3 and 11·3% for bladder and rectum, respectively) and worsening of the HI (0·095–0·322) but with no significant effect on tumour control probability. Furthermore, OARs volumes, distances between OARs and PTV and their joint volumes had stronger correlations with OARs’ mean doses.

Conclusion

Enforcement of target dose constraints was more effective on the improvement of HIs for the patients with initial high HI values at low dose constraints’ priorities. Reducing the priority had more effects on the OARs sparing compared to HI, especially for the patients with high OAR doses in high priority plans. This can be attributed to smaller distances or greater joint volumes between the OARs and PTV.

Keywords

IMRTOAR sparingprostate cancerPTV dose homogeneitytreatment planning
Type
Original Article
Information
Journal of Radiotherapy in Practice , Volume 18 , Issue 3 , September 2019 , pp. 232 - 238
Copyright
© Cambridge University Press 2019 

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Footnotes

Cite this article: Banaei A, Hashemi B, Bakhshandeh M, Mofid B. (2019). Trade-off between the conflicting planning goals in correlation with patient’s anatomical parameters for intensity-modulated radiotherapy of prostate cancer patients. Journal of Radiotherapy in Practice18: 232–238. doi: 10.1017/S1460396919000025

References

1. Tanaka, H, Yamaguchi, T, Hachiya, K. et al. Treatment outcomes and late toxicities of intensity-modulated radiation therapy for 1091 Japanese patients with localized prostate cancer. Rep Pract Oncol Radiother 2018; 23 (1): 28–33.10.1016/j.rpor.2017.11.002Google Scholar
2. Halperin, EC, Brady, LW, Perez, CA. Perez & Brady’s principles and practice of radiation oncology, 6th edition. Philadelphia, USA: Lippincott Williams & Wilkins, 2013.Google Scholar
3. Nelms, BE, Robinson, G, Markham, J et al. Variation in external beam treatment plan quality: an inter-institutional study of planners and planning systems. Pract Radiat Oncol 2012; 2 (4): 296–305.10.1016/j.prro.2011.11.012Google Scholar
4. Sun, L, Smith, W, Ghose, A, Kirkby, C. A quantitative assessment of the consequences of allowing dose heterogeneity in prostate radiation therapy planning. J Appl Clin Med Phys 2018; 19: 580–590.10.1002/acm2.12424Google Scholar
5. Craft, D, Khan, F, Young, M, Bortfeld, T. The price of target dose uniformity. Int J Radiat Oncol Biol Phys 2016; 96: 913–914.10.1016/j.ijrobp.2016.07.033Google Scholar
6. Matzinger, O, Poortmans, P, Giraud, JY et al. Quality assurance in the22991 EORTC ROG trial in localized prostate cancer: dummy run and individual case review. Radiother Oncol. 2009; 90 (3): 285–290.10.1016/j.radonc.2008.10.022Google Scholar
7. Pollack, A, Walker, G, Horwitz, EM et al. Randomized trial of hypofractionated external-beam radiotherapy for prostate cancer. J Clin Oncol 2013; 31 (31): 3860–3868.10.1200/JCO.2013.51.1972Google Scholar
8. Pollack, A, Hanlon, AL, Horwitz, EM et al. Dosimetry and preliminary acute toxicity in the first 100 men treated for prostate cancer on a randomized hypofractionation dose escalation trial. Int J Radiat Oncol Biol Phys 2006; 64 (2): 518–526.10.1016/j.ijrobp.2005.07.970Google Scholar
9. International Commission on Radiation Units and Measurements. ICRU Report 50. Prescribing, recording, and reporting photon beam therapy. J ICRU, Bethesda, MD, 1993; 21(November): 357–360.10.1118/1.597396Google Scholar
10. International Commission on Radiation Units and Measurements. ICRU Report 62. Prescribing, recording and reporting photon beam therapy (supplement to ICRU report 50). J ICRU Bethesda, MD, 1999.Google Scholar
11. International Commission on Radiation Units and Measurements. ICRU Report 83. Prescribing, recording, and reporting photon-beam intensity-modulated radiation therapy (IMRT). J ICRU, 2010;10(1).Google Scholar
12. Tol, JP, Dahele, M, Doornaert, P et al. Toward optimal organ at risk sparing in complex volumetric modulated arc therapy: an exponential trade-off with target volume dose homogeneity. Med Phys 2014; 41 (2): 021722.10.1118/1.4862521Google Scholar
13. Craft, D, McQuaid, D, Wala, J, Chen, W, Salari, E, Bortfeld, T. Multicriteria VMAT optimization. Med Phys 2012; 39 (2): 686–696.10.1118/1.3675601Google Scholar
14. Paddick, I. A simple scoring ratio to index the conformity of radiosurgical treatment plans. J. Neurosurg 2000; 93 (Suppl 3): 219–222.10.3171/jns.2000.93.supplement_3.0219Google Scholar
15. Emami, B, Lyman, J, Brown, A et al. Tolerance of normal tissue to therapeutic irradiation. Int J Radiat Oncol Biol Phys 1991; 21 (1): 109–122.10.1016/0360-3016(91)90171-YGoogle Scholar
16. Milano, MT, Constine, LS, Okunieff, P. Normal tissue tolerance dose metrics for radiation therapy of major organs. Semin Radiat Oncol. 2007; 17 (2): 131–140.Google Scholar
17. Niemierko, A, Goitein, M. Implementation of a model for estimating tumor control probability for an inhomogeneously irradiated tumor. Radiother Oncol. 1993; 29: 140–147.10.1016/0167-8140(93)90239-5Google Scholar
18. Gay, HA, Niemierko, A. A free program for calculating EUD‐based NTCP and TCP in external beam radiotherapy. Phys Med. 2007; 23: 115–125.10.1016/j.ejmp.2007.07.001Google Scholar
19. Wall, PD, Carver, RL, Fontenot, JD. An improved distance-to-dose correlation for predicting bladder and rectum dose-volumes in knowledge-based VMAT planning for prostate cancer. Phys Med Biol 2018; 63 (1): 015035.10.1088/1361-6560/aa9a30Google Scholar
20. Landoni, V, Fiorino, C, Cozzarini, C, Sanguineti, G, Valdagni, R, Rancati, T. Predicting toxicity in radiotherapy for prostate cancer. Phys Med. 2016; 32: 521–532.10.1016/j.ejmp.2016.03.003Google Scholar
21. Goitein, M. Causes and consequences of inhomogeneous dose distributions in radiation therapy. Int J Radiat Oncol Biol Phys 1986; 12: 701–704.10.1016/0360-3016(86)90084-2Google Scholar
22. Nielsen, TB, Hansen, O, Schytte, T, Brink, C. Inhomogeneous dose escalation increases expected local control for NSCLC patients with lymph node involvement without increased mean lung dose. Acta Oncol. 2014; 53: 119–125.10.3109/0284186X.2013.790560Google Scholar
23. Balderson, MJ, Kirkby, C. Potential implications of the bystander effect on TCP and EUD when considering target volume dose heterogeneity. Int J Radiat Biol 2015; 91: 54–61.10.3109/09553002.2014.942014Google Scholar
24. Mavroidis, P, Komisopoulos, G, Buckey, C et al. Radiobiological evaluation of prostate cancer IMRT and conformal-RT plans using different treatment protocols. Phys Medica Eur J Med Phys 2017; 40: 33–41.Google Scholar