Dose-volume consistency and radiobiological characterization between prostate IMRT and VMAT plans

James Chow, Runqing Jiang, Alexander Kiciak

Abstract


Purpose: Dose-volume consistency of the planning target volume (PTV) and rectum for the prostate intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) plans were evaluated and compared. Dependences of radiobiological parameters of the prostate and rectum on the PTV and rectal volume were also investigated.

Methods: From 40 prostate IMRT and 50 VMAT patients treated with the same prescription (78 Gy per 39 fractions) and dose-volume criteria in the inverse planning, the prostate tumour control probability (TCP), rectal equivalent uniform dose (EUD) and rectal normal tissue complication probability (NTCP) were calculated. The dose-volume consistency of the PTV and rectum, demonstrating the variability of dose-volume histogram (DVH) among patients, was defined and calculated as per the deviation between the corresponding and mean DVH.

Results: For the IMRT plans, the prostate TCP was found increasing with the PTV with a rate equal to 1.05 × 10-3 % cm-3, which was lower than 1.11 × 10-3 % cm-3 for the VMAT plans. Both the rectal EUD and rectal NTCP were found decreasing with the rectal volume. The decrease rates for the IMRT plans (EUD = 0.47 × 10-3 Gy cm-3 and NTCP = 3.94 × 10-2 % cm-3) were higher than those for the VMAT (EUD = 0.28 × 10-3 Gy cm-3 and NTCP = 2.61 × 10-2 % cm-3).

Conclusion: For the dose-volume consistency, small prostate TCP variation could be achieved by decreasing the dose-volume variability among the IMRT and VMAT plans. However, dependences of the rectal EUD and rectal NTCP on the dose-volume variability were not significant. It is concluded that maintaining a good dose-volume consistency in prostate plans can decrease the prostate TCP variation among the IMRT and VMAT patients. However, dose-volume variability is not affected by variations of the rectal EUD and rectal NTCP. 


Keywords


Prostate IMRT, Prostate VMAT, Dose-volume histogram, Prostate TCP, Rectal NTCP, Rectal EUD

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References


Hummel S, Simpson EL, Hemingway P, et al. Intensity-modulated radiotherapy for the treatment of prostate cancer: a systematic review and economic evaluation. Health Technol Assess. 2010;14:1-108.

Hall EJ, Wu C. Radiation-induced second cancers: the impact of 3D-CRT and IMRT. Int. J. Radiation Oncology Biol. Phys. 2003;56:83-8.

Zelefsky MJ, Chan H, Hunt M, et al. Long-term outcome of high dose intensity modulated radiation therapy of patients with clinically localized prostate cancer. J Urology. 2006;176:1415-19.

Veldeman L, Madani I, Hulstaert F, et al. Evidence behind use of intensity-modulated radiotherapy: a systematic review of comparative clinical studies. Lancet Oncol. 2008;9:367-75.

Adams EJ, Convery DJ, Cosqrove VP et al. Clinical implementation of dynamic and step-and-shoot IMRT to treat prostate cancer with high risk of pelvic lymph node involvement. Radiother Oncol. 2004;70:1-10.

Grigorov GN, Chow JCL, Barnett RB. Dosimetry limitations and a dose correction methodology for step-and-shoot IMRT. Phys Med Biol. 2006;51:637-52.

Otto K. Volumetric modulated arc therapy: IMRT in a single gantry arc. Med. Phys. 2008;35:310–17.

Yu CX. Intensity-modulated arc therapy with dynamic multileaf collimation: an alternative to tomotherapy. Phys. Med. Biol. 1995;40:1435–39.

Chow JCL, Grigorov GN, Yazdani N. SWIMRT: a graphical user interface using sliding window algorithm to construct a fluence map machine file. J Appl Clin Med Phys. 2006;7:69-85.

Rao M, Yang W, Chen F, et al. Comparison of Elektra VMAT with helical tomotherapy and fixed field IMRT: Plan quality, delivery efficiency and accuracy. Med. Phys. 2010;37:1350–59.

Cao D, Afghan MKN, Ye J, et al. A generalized inverse planning tool for volumetric modulated arc therapy. Phys. Med. Biol. 2009;54:6725–38.

Shepard DM, Cao D, Afghan MKN, et al. An arc-sequencing algorithm for intensity modulated arc therapy. Med. Phys. 2007;34:464–70.

Chow JCL, Jiang R. Dosimetry estimation on variations of patient size in prostate volumetric-modulated arc therapy. Med. Dosim. 2013;38:42-7.

Chow JCL, Jiang R. Prostate volumetric-modulated arc therapy: dosimetry and radiobiological model variation between the single-arc and double-arc technique. J Appl Clin Med Phys. 2013;14:3-12.

Letourneau D, Publicover J, Kozelka J, et al. Novel dosimetric phantom for quality assurance of volumetric modulated arc therapy. Med. Phys. 2009;36:1813–21.

Haga A, Nakagawa K, Shiraishi K, et al. Quality assurance of volumetric modulated arc therapy using Elekta Synergy. Acta Oncol. 2009;48:1193–97.

Chow JCL, Jiang R. Comparison of dosimetric variation between prostate IMRT and VMAT due to patient’s weight loss: Patient and phantom study. Rep Pract Oncol Radiother. 2013;18:272-78.

Davidson MTM, Blake SJ, Batchelar DL, et al. Assessing the role of volumetric modulated arc therapy (VMAT) relative to IMRT and helical tomotherapy in the management of localized, locally advanced, and post-operative prostate cancer. Int. J. Radiation Oncology Biol. Phys. 2011;80:1550–58.

Hardcastle N, Tome WA, Foo K, et al. Comparison of prostate IMRT and VMAT biologically optimized treatment plans. Med. Dosim. 2011;36:292–98.

Iori M, Cattaneo G, Cagni E, et al. Dose-volume and biological-model based comparison between helical tomotherapy and (inverse-planned) IMAT for prostate tumours. Radiother Oncol. 2008;88:34–45.

Zhang P, Happersett L, Hunt M, et al. Volumetric modulated arc therapy: planning and evaluation for prostate cancer cases. Int. J. Radiation Oncology Biol. Phys. 2010;76:1456–62.

Wolff D, Stieler F, Welzel G, et al. Volumetric modulated arc therapy (VMAT) vs. serial tomotherapy, step-and-shoot IMRT and 3D-conformal RT for treatment of prostate cancer. Radiother Oncol. 2009;93:226–33.

Wu B, Ricchetti F, Sanguineti G et al. Patient geometry-driven information retrieval for IMRT treatment plan quality control. Med Phys. 2009;36:5497-505.

Chow JCL. Radiation treatment planning based on big data of previously treated plans using the Gaussian error function model. Proceedings, HPCS 2015, Advanced Computing and Big Data: Driving Competitiveness and Discovery.2015:12.

Chanyavanich V, Das SK, Lee WR, et al. Knowledge-based IMRT treatment planning for prostate cancer. Med Phys. 2011;38:2512-22.

Good D, Lo J, Lee WR, et al. A knowledge-based approach to improving and homogenizing intensity modulated radiation therapy planning quality among treatment centers: an example application to prostate cancer planning. Int J Radiat Oncol Biol Phys. 2013;87:176-81.

Nwankwo O, Mekdash H, Shihono DSK, et al. Knowledge-based radiation therapy (KBRT) treatment planning versus planning by experts: validation of a KBRT algorithm for prostate cancer treatment planning. Radiat Oncol. 2015;10:111.

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;2:296-305.

Zhu X, Ge Y, Li T, et al. A planning quality evaluation tool for prostate adaptive IMRT based on machine learning. Med Phys. 2011;38:719-26.

Okunieff P, Morgan D, Niemierko A, et al. Radiation dose response of human tumours. Int J Radiat Oncol Biol Phys. 1995;32:1227-37.

Niemierko A. A generalized concept of equivalent uniform dose (EUD). Med Phys. 1999;26:1100.

Shan W, Chow JCL, Markel D, et al. Rectal equivalent uniform dose analysis on the prostate IMRT for interfraction organ motion using the Gaussian error function. Med Phys. 2011;38:3640.

Lyman JT. Complication probability as assessed from dose-volume histogram. Radiat Res. 1985;104:S13-19.

Burman C, Kuther GJ, Emami B, et al. Fitting of normal tissue tolerance data to an analytic function. Int J Tadiat Oncol Biol Phys. 1991;21:123-35.

Kutcher GJ, Burman C, Brewster L, et al. Histogram reduction method for calculating complication probability for three-dimensional treatment planning evaluation. Int J Radiat Oncol Biol Phys. 1991;21:137-46.

Jiang R, Barnett RB, Chow JCL, et al. The use of spatial dose gradients and probability density function to evaluate the effect of internal organ motion for prostate IMRT treatment planning. Phys Med Biol. 2007;52:1469-84.




DOI: http://dx.doi.org/10.14319/ijcto.44.7

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