Evaluation of heterogeneity dose distributions for Stereotactic Radiotherapy (SRT): comparison of commercially available Monte Carlo dose calculation with other algorithms

Radiation Oncology

Keiichi Nakagawa¹  Akihiro Haga¹  Akira Sakumi¹  Yoshio Iwai²  Naoya Saotome¹  Hideomi Yamashita¹  Wataru Takahashi¹ 

[1] Department of Radiology, University of Tokyo Hospital, Hongo, Bunkyo-ku, Tokyo, Japan;Elekta KK, 3-9-1 Shibaura, Minato-ku, Tokyo 108-0023, Japan

关键词: Tissue inhomogeneities;    Lung cancer;    Stereotactic body radiotherapy (SBRT);    Calculation algorithm;    Monte Carlo;   

Others  :  1160896
DOI  :  10.1186/1748-717X-7-20

 received in 2011-09-12, accepted in 2012-02-09,  发布年份 2012

【 摘 要 】

Background

The purpose of this study was to compare dose distributions from three different algorithms with the x-ray Voxel Monte Carlo (XVMC) calculations, in actual computed tomography (CT) scans for use in stereotactic radiotherapy (SRT) of small lung cancers.

Methods

Slow CT scan of 20 patients was performed and the internal target volume (ITV) was delineated on Pinnacle³. All plans were first calculated with a scatter homogeneous mode (SHM) which is compatible with Clarkson algorithm using Pinnacle³ treatment planning system (TPS). The planned dose was 48 Gy in 4 fractions. In a second step, the CT images, structures and beam data were exported to other treatment planning systems (TPSs). Collapsed cone convolution (CCC) from Pinnacle³, superposition (SP) from XiO, and XVMC from Monaco were used for recalculating. The dose distributions and the Dose Volume Histograms (DVHs) were compared with each other.

Results

The phantom test revealed that all algorithms could reproduce the measured data within 1% except for the SHM with inhomogeneous phantom. For the patient study, the SHM greatly overestimated the isocenter (IC) doses and the minimal dose received by 95% of the PTV (PTV95) compared to XVMC. The differences in mean doses were 2.96 Gy (6.17%) for IC and 5.02 Gy (11.18%) for PTV95. The DVH's and dose distributions with CCC and SP were in agreement with those obtained by XVMC. The average differences in IC doses between CCC and XVMC, and SP and XVMC were -1.14% (p = 0.17), and -2.67% (p = 0.0036), respectively.

Conclusions

Our work clearly confirms that the actual practice of relying solely on a Clarkson algorithm may be inappropriate for SRT planning. Meanwhile, CCC and SP were close to XVMC simulations and actual dose distributions obtained in lung SRT.

【 授权许可】

   
2012 Takahashi et al; licensee BioMed Central Ltd.

【 图 表 】

Figure 1.

Figure 2.

Figure 3.

Figure 4.

Figure 5.

【 参考文献 】

• [1]Jemal A, Bray F, Center MM, Ferlay J, Ward E, Forman D: Global cancer statistics. CA Cancer J Clin 2011, 61(2):69-90. Epub 2011 Feb 4
• [2]Matsuo Y, Shibuya K, Nagata Y, Takayama K, Norihisa Y, Mizowaki T, Narabayashi M, Sakanaka K, Hiraoka M: Prognostic Factors in Stereotactic Body Radiotherapy for Non-Small-Cell Lung Cancer. Int J Radiat Oncol Biol Phys 2010. Epub 2010 May 14
• [3]Baumann P, Nyman J, Hoyer M, Wennberg B, Gagliardi G, Lax I, Drugge N, Ekberg L, Friesland S, Johansson KA, Lund JA, Morhed E, Nilsson K, Levin N, Paludan M, Sederholm C, Traberg A, Wittgren L, Lewensohn R: Outcome in a prospective phase II trial of medically inoperable stage I non-small-cell lung cancer patients treated with stereotactic body radiotherapy. J Clin Oncol 2009, 27(20):3290-6. Epub 2009 May 4
• [4]Herman Tde L, Gabrish H, Herman TS, Vlachaki MT, Ahmad S: Impact of tissue heterogeneity corrections in stereotactic body radiation therapy treatment plans for lung cancer. J Med Phys 2010, 35(3):170-3.
• [5]Chang D, Liu C, Dempsey JF, Palta JR, Kopea J, Louis D, Morris C, Chopra R, Olivier KR: Predicting changes in dose distribution to tumor and normal tissue when correcting for heterogeneity in radiotherapy for lung cancer. Am J Clin Oncol 2007, 30(1):57-62.
• [6]Hiraoka M, Ishikura S: A Japan clinical oncology group trial for stereotactic body radiation therapy of non-small cell lung cancer. J Thorac Oncol 2007, 2(7 Suppl 3):S115-7.
• [7]Knoos T, Ahnesjo A, Nilsson P, Weber L: Limitations of a pencil beam approach to photon dose calculations in lung tissue. Phys Med Biol 1995, 40:1411-1420.
• [8]Aarup LR, Nahum AE, Zacharatou C, Juhler-Nøttrup T, Knöös T, Nyström H, Specht L, Wieslander E, Korreman SS: The effect of different lung densities on the accuracy of various radiotherapy dose calculationmethods: implications for tumour coverage. Radiother Oncol 2009, 91(3):405-14. Epub 2009, 16
• [9]Dobler B, Walter C, Knopf A, Fabri D, Loeschel R, Polednik M, Schneider F, Wenz F, Lohr F: Optimization of extracranial stereotactic radiation therapy of small lung lesions using accurate dose calculation algorithms. Radiat Oncol 2006, 1:45. BioMed Central Full Text
• [10]Fotina I, Winkler P, Künzler T, Reiterer J, Simmat I, Georg D: Advanced kernel methods vs. Monte Carlo-based dose calculation for high energy photon beams. Radiother Oncol 2009, 93(3):645-53. Epub 2009 Nov 18
• [11]Koelbl O, Krieger T, Haedinger U, Sauer O, Flentje M: Influence of Calculation Algorithm on Dose Distribution in Irradiation of Non-Small Cell Lung Cancer (NSCLC) Collapsed Cone Versus Pencil Beam. Strahlenther Onkol 2004, 180:783-788.
• [12]Fragoso M, Wen N, Kumar S, Liu D, Ryu S, Movsas B, Munther A, Chetty IJ: Dosimetric verification and clinical evaluation of a new commercially available Monte Carlo-based dose algorithm for application in stereotactic body radiation therapy (SBRT) treatment planning. Phys Med Biol 2010, 55(16):4445-64. Epub 2010
• [13]Wulf J, Hädinger U, Oppitz U, Olshausen B, Flentje M: Stereotactic radiotherapy of extracranial targets: CT-simulation and accuracy of treatment in the stereotactic body frame. Radiother Oncol 2000, 57(2):225-36.
• [14]Takeda A, Kunieda E, Shigematsu N, Hossain DM, Kawase T, Ohashi T, Fukada J, Kawaguchi O, Uematsu M, Takeda T, Takemasa K, Takahashi T, Kubo A: Small lung tumors: long-scan-time CT for planning of hypofractionated stereotactic radiation therapy--initial findings. Radiology 2005, 237(1):295-300. Epub 2005 Aug 18
• [15]Ahnesjö A: Collapsed cone convolution of radiant energy for photon dose calculation in heterogeneous media. Med Phys 1989, 16:577-92.
• [16]Yamashita H, Nakagawa K, Nakamura N, Koyanagi H, Tago M, Igaki H, Shiraishi K, Sasano N, Ohtomo K: Exceptionally high incidence of symptomatic grade 2-5 radiation pneumonitis after stereotactic radiation therapy for lung tumors. Radiat Oncol 2007, 2:21. BioMed Central Full Text
• [17]Mackie TR, Bielajew AF, Rogers DW, Battista JJ: Generation of photon energy deposition kernels using the EGS Monte Carlo code. Phys Med Biol 1988, 33(1):1-20.
• [18]Miften MM, Beavis AW, Marks LB: Influence of dose calculation model on treatment plan evaluation in conformal radiotherapy: a three-case study. Med Dosim 2002, 27(1):51-7.
• [19]Kawrakow I, Fippel M, Friedrich K: 3D electron dose calculation using a Voxel based Monte Carlo algorithm (VMC). Med Phys 1996, 23(4):445-57.
• [20]Fippel M, Laub W, Huber B, Nüsslin F: Experimental investigation of a fast Monte Carlo photon beam dose calculation algorithm. Phys Med Biol 1999, 44(12):3039-54.
• [21]Fotina I, Kragl G, Kroupa B, Trausmuth R, Georg D: Clinical comparison of dose calculation using the enhanced collapsed cone algorithm vs. a new Monte Carlo algorithm. Strahlenther Onkol 2011, 187(7):433-41. Epub 2011 Jun 27
• [22]Fippel M, Nüsslin F: Foundations of the Monte Carlo method for dose calculation in radiotherapy. Z Med Phys 2001, 11(2):73-82.
• [23]Fogliata A, Vanetti E, Albers D, Brink C, Clivio A, Knöös T, Nicolini G, Cozzi L: On the dosimetric behaviour of photon dose calculation algorithms in the presence of simple geometric heterogeneities: comparison with Monte Carlo calculations. Phys Med Biol 2007, 52(5):1363-85. Epub 2007 Feb 8
• [24]Panettieri V, Wennberg B, Gagliardi G, Duch MA, Ginjaume M, Lax I: SBRT of lung tumours: Monte Carlo simulation with PENELOPE of dose distributions including respiratory motion and comparison with different treatment planning systems. Phys Med Biol 2007, 52(14):4265-81.
• [25]Chen H, Lohr F, Fritz P, Wenz F, Dobler B, Lorenz F, Mühlnickel W: Stereotactic, single-dose irradiation of lung tumors: a comparison of absolute dose and dose distribution between pencil beam and Monte Carlo algorithms based on actual patient CT scans. Int J Radiat Oncol Biol Phys 2010, 78(3):955-63. Epub 2010 Feb 18