Hostname: page-component-cd9895bd7-gxg78 Total loading time: 0 Render date: 2024-12-26T21:16:03.610Z Has data issue: false hasContentIssue false
  • English
  • Français

Evaluating small field dosimetry with the Acuros XB (AXB) and analytical anisotropic algorithm (AAA) dose calculation algorithms in the eclipse treatment planning system

Published online by Cambridge University Press:  29 April 2019

Sepideh Behinaein ,
Ernest Osei Open the ORCID record for Ernest Osei [Opens in a new window] ,
Johnson Darko ,
Paule Charland  and
Dylan Bassi
Sepideh Behinaein
Affiliation:
Department of Medical Physics, Grand River Regional Cancer Centre, Kitchener, Canada
Ernest Osei*
Affiliation:
Department of Medical Physics, Grand River Regional Cancer Centre, Kitchener, Canada Department of Physics and Astronomy, University of Waterloo, Waterloo, Canada Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, Canada Department of Systems Design Engineering, University of Waterloo, Waterloo, Canada
Johnson Darko
Affiliation:
Department of Medical Physics, Grand River Regional Cancer Centre, Kitchener, Canada Department of Physics and Astronomy, University of Waterloo, Waterloo, Canada Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, Canada
Paule Charland
Affiliation:
Department of Medical Physics, Grand River Regional Cancer Centre, Kitchener, Canada Department of Physics and Astronomy, University of Waterloo, Waterloo, Canada
Dylan Bassi
Affiliation:
Department of Physics and Astronomy, University of Waterloo, Waterloo, Canada
*
Author for correspondence: Ernest Osei, Grand River Regional Cancer Centre, 835 King Street West, Kitchener, Ontario N2G1G3, Canada. Tel: 519 749 4300 ext. 5407. E-mail: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

Background:

An increasing number of external beam treatment modalities including intensity modulated radiation therapy, volumetric modulated arc therapy (VMAT) and stereotactic radiosurgery uses very small fields for treatment planning and delivery. However, there are major challenges in small photon field dosimetry, due to the partial occlusion of the direct photon beam source’s view from the measurement point, lack of lateral charged particle equilibrium, steep dose-rate gradient and volume averaging effect of the detector response and variation of the energy fluence in the lateral direction of the beam. Therefore, experimental measurements of dosimetric parameters such as percent depth doses (PDDs), beam profiles and relative output factors (ROFs) for small fields continue to be a challenge.

Materials and Methods:

In this study, we used a homogeneous water phantom and the heterogeneous anthropomorphic stereotactic end-to-end verification (STEEV) head phantom for all dose measurements and calculations. PDDs, lateral dose profiles and ROFs were calculated in the Eclipse Treatment Planning System version 13·6 using the Acuros XB (AXB) and the analytical anisotropic algorithms (AAAs) in a homogenous water phantom. Monte Carlo (MC) simulations and measurements using the Exradin W1 Scintillator were also accomplished for four photon energies: 6 MV, 6FFF, 10 MV and 10FFF. Two VMAT treatment plans were generated for two different targets: one located in the brain and the other in the neck (close to the trachea) in the head phantom (CIRS, Norfolk, VA, USA). A Varian Truebeam linear accelerator (Varian, Palo Alto, CA, USA) was used for all treatment deliveries. Calculated results with AXB and AAA were compared with MC simulations and measurements.

Results:

The average difference of PDDs between W1 Exradin Scintillator measurements and MC simulations, AAA and AXB algorithm calculations were 1·2, 2·4 and 3·2%, respectively, for all field sizes and energies. AXB and AAA showed differences in ROF of about 0·3 and 2·9%, respectively, compared with W1 Exradin Scintillator measured values. For the target located in the brain in the head phantom, the average dose difference between W1 Exradin Scintillator and the MC simulations, AAA and AXB were 0·2, 3·2 and 2·7%, respectively, for all field sizes. Similarly, for the target located in the neck, the respective dose differences were 3·8, 5·7 and 3·5%.

Conclusion:

In this study, we compared dosimetric parameters such as PDD, beam profile and ROFs in water phantom and isocenter point dose measurements in an anthropomorphic head phantom representing a patient. We observed that measurements using the W1 Exradin scintillator agreed well with MC simulations and can be used efficiently for dosimetric parameters such as PDDs and dose profiles and patient-specific quality assurance measurements for small fields. In both homogenous and heterogeneous media, the AXB algorithm dose prediction agrees well with MC and measurements and was found to be superior to the AAA algorithm.

Keywords

Acuros XBanalytical anisotropic algorithmEGSnrc Monte Carlo simulationExradin W1 Scintillator measurementsmall field dosimetry
Type
Original Article
Information
Journal of Radiotherapy in Practice , Volume 18 , Issue 4 , December 2019 , pp. 353 - 364
Copyright
© Cambridge University Press 2019 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Sharma, S D. Challenges of small photon field dosimetry are still challenging. J Med Phys 2014; 39: 131–132.10.4103/0971-6203.138998CrossRefGoogle ScholarPubMed
Aspradakis, M, Byrne, J, Palmans, H et al. Small field MV photon dosimetry. IPEM Report No. 103. York, UK: Institute of Physics and Engineering in Medicine, 2010.Google Scholar
Das, I J, Ding, G X, Ahnesjö, A. Small field: nonequilibrium radiation dosimetry. Med Phys 2008; 35: 206–215.10.1118/1.2815356CrossRefGoogle ScholarPubMed
Massillon-J, L G. Dosimetry in steep dose-rate gradient radiation fields: a challenge in clinical applications. Eleventh Mexican Symposium on Medical Physics AIP Conference Proceeding, Mexico City, (Mexico). 2010; 1310: 23–28.Google Scholar
Alfonso, R, Andreo, P, Capote, R et al. A new formalism for reference dosimetry of small and nonstandard fields. Med Phys 2008; 35: 5179–5186.10.1118/1.3005481CrossRefGoogle ScholarPubMed
International Atomic Energy Agency. Dosimetry of Small Static Fields Used in External Beam Radiotherapy. Technical Reports Series No. 483, IAEA, Vienna. 2017: 1–211.Google Scholar
Carrasco, P, Jornet, N, Jordi, O et al. Characterization of the Exradin W1 scintillator for use in radiotherapy. Med Phys 2014; 42: 297–304.10.1118/1.4903757CrossRefGoogle Scholar
Laub, WU, Wong, T. The volume effect of detectors in the dosimetry of small fields used in IMRT. Med Phys 2003; 30: 341–347.10.1118/1.1544678CrossRefGoogle ScholarPubMed
Le Roy, M, De Carlan, L, Delaunay, F et al. Assessment of small volume ionization chambers as reference dosimeters in high-energy photon beams. Phys Med Biol 2011; 56: 5637–5650.10.1088/0031-9155/56/17/011CrossRefGoogle Scholar
Andersson, J, Kaiser, F J, Gómez, F et al. A comparison of different experimental methods for general recombination correction for liquid ionization chambers. Phys Med Biol 2012; 57: 7161–7175.10.1088/0031-9155/57/21/7161CrossRefGoogle ScholarPubMed
Pardo-Montero, J, Gómez, F. Determining charge collection efficiency in parallel-plate liquid ionization chambers. Phys Med Biol 2009; 54: 3677–3689.10.1088/0031-9155/54/12/005CrossRefGoogle ScholarPubMed
Chung, E, Davis, S, Seuntjens, J. Experimental analysis of general ion recombination in a liquid-filled ionization chamber in high-energy photon beams. Med Phys 2013; 40 (6): 062104-1–7.10.1118/1.4805109CrossRefGoogle Scholar
Eklund, K. Modeling silicon diode dose response in radiotherapy fields using fluence pencil kernels, PhD Thesis, Uppsala University (2010).Google Scholar
Scott, A J, Kumar, S, Nahum, A E, Fenwick, J D. Characterizing the influence of detector density on dosimeter response in non-equilibrium small photon fields. Phys Med Biol 2012; 57: 4461–4476.10.1088/0031-9155/57/14/4461CrossRefGoogle ScholarPubMed
Gagnon, J C, Thériault, D, Guillot, M et al. Dosimetric performance and array assessment of plastic scintillation detectors for stereotactic radiosurgery quality assurance. Med Phys 2012; 39: 429–436.10.1118/1.3666765CrossRefGoogle ScholarPubMed
Francescon, P, Cora, S, Cavedon, C et al. Use of a new type of radiochromic film, a new parallel-plate micro-chamber, MOSFETs, and TLD 800 microcubes in the dosimetry of small beams. Med Phys 1998; 125: 503–511.10.1118/1.598227CrossRefGoogle Scholar
Alnawaf, H, Buston, M J, Cheuung, T et al. Scanning orientation and polarization effects for XRQA radiochromic film. Phys Med 2010; 26: 216–219.10.1016/j.ejmp.2010.01.003CrossRefGoogle ScholarPubMed
Ramani, R, Russell, S, O’Brien, P. Clinical dosimetry using MOSFETs. Int J Radiat Oncol Biol Phys 1997; 37: 959–964.10.1016/S0360-3016(96)00600-1CrossRefGoogle ScholarPubMed
Jursinic, P A. Characterization of optically stimulated luminescent dosimeters, OSLDs, for clinical dosimetric measurements. Med Phys 2007; 34: 4594–4604.10.1118/1.2804555CrossRefGoogle ScholarPubMed
Fogliata, A, Cozzi, L. Dose calculation algorithm accuracy for small fields in non-homogeneous media: the lung SBRT case. Phys Med 2017; 44: 157–162.10.1016/j.ejmp.2016.11.104CrossRefGoogle ScholarPubMed
Cassell, K J, Hobday, P A, Parker, R P. The implementation of a generalized Batho inhomogeneity correction for radiotherapy planning with direct use of CT numbers. Phys Med Biol 1981; 26: 825–833.10.1088/0031-9155/26/5/002CrossRefGoogle Scholar
Sontag, M R, Cunningham, J R. The equivalent tissue-air ratio method for making absorbed dose calculations in a heterogeneous medium. Radiology 1978; 129: 787–794.10.1148/129.3.787CrossRefGoogle Scholar
Engelsman, M, Damen, E M, Koken, P W et al. Impact of simple tissue inhomogeneity correction algorithms on conformal radiotherapy of lung tumours. Radiother Oncol 2001; 60: 299–309.10.1016/S0167-8140(01)00387-5CrossRefGoogle ScholarPubMed
Tillikainen, L, Helminen, H, Torsti, T et al. A 3D pencil-beam-based superposition algorithm for photon dose calculation in heterogeneous media. Phys Med Biol 2008; 53: 3821–3839.10.1088/0031-9155/53/14/008CrossRefGoogle ScholarPubMed
Ahnesjö, A, Andreo, P, Brahme, A. Calculation and application of point spread functions for treatment planning with high energy photon beams. Acta Oncol 1987; 26: 49–56.10.3109/02841868709092978CrossRefGoogle ScholarPubMed
Vassiliev, O N, Wareing, T A, McGhee, J et al. Validation of a new grid-based Boltzmann equation solver for dose calculation in radiotherapy with photon beams. Phys Med Biol 2010; 55: 581–598.10.1088/0031-9155/55/3/002CrossRefGoogle ScholarPubMed
Han, T, Mikell, J K, Salehpour, M, Mourtada, F. Dosimetric comparison of Acuros XB deterministic radiation transport method with Monte Carlo and model-based convolution methods in heterogeneous media. Med Phys 2011; 38 (5): 2651–2664.10.1118/1.3582690CrossRefGoogle ScholarPubMed
Fogliata, A, Vanetti, E, Albers, D et al. On the dosimetric behaviour of photon dose calculation algorithms in the presence of simple geometric heterogeneities: comparison with Monte Carlo calculations. Phys Med Bio 2007; 52: 1363–1385.10.1088/0031-9155/52/5/011CrossRefGoogle ScholarPubMed
Hasenbalg, F, Neuenschwander, H, Mini, R, Born, E J. Collapsed cone convolution and analytical anisotropic algorithm dose calculations compared to VMC++ Monte Carlo simulations in clinical cases. Phys Med Biol 2007; 52: 3679–3691.10.1088/0031-9155/52/13/002CrossRefGoogle ScholarPubMed
Hoffmann, L, Alber, M, Söhn, M, Elstrøm, U V. Validation of the Acuros XB dose calculation algorithm versus Monte Carlo for clinical treatment plans. Med Phys 2018; 45: 3909–3915.10.1002/mp.13053CrossRefGoogle Scholar
Stathakis, S, Esquivel, C, Quino, L V. Accuracy of the small field dosimetry using the Acuros XB dose calculation algorithm within and beyond heterogeneous media for 6 MV photon beams. Int J Med Phys Clin Eng Radiat Oncol 2012; 1: 78–87.10.4236/ijmpcero.2012.13011CrossRefGoogle Scholar
Zavan, R, McGeachy, P, Madamesila, J et al. Verification of Acuros XB dose algorithm using 3D printed low-density phantoms for clinical photon beams. J Appl Clin Med Phys 2018; 19: 32–43.10.1002/acm2.12299CrossRefGoogle Scholar
Qin, Y, Gardner, S J, Kim, J et al. Technical Note: evaluation of plastic scintillator detector for small field stereotactic patient-specific quality assurance. Med Phys 2017; 44: 5509–5516.10.1002/mp.12471CrossRefGoogle Scholar
Godson, H F, Ravikumar, M, Sathiyan, S et al. Analysis of small field percent depth dose and profiles: comparison of measurements with various detectors and effects of detector orientation with different jaw settings. Med Phys 2016; 41: 12–20.Google ScholarPubMed
Pasquino, M, Cutaia, C, Radici, L et al. Dosimetric characterization and behaviour in small X-ray fields of a microchamber and a plastic scintillator detector. Br Radiol 2017; 90: 20160596, 1–8.Google Scholar
Das, I J, Cheng, C, Watts, R J et al. Accelerator beam data commissioning equipment and procedures: report of the TG-106 of the Therapy Physics Committee of the AAPM. Med Phys 2008; 35: 4186–4214.10.1118/1.2969070CrossRefGoogle ScholarPubMed
Hoffmann, L, Jørgensen, M B, Muren, L P, Petersen, J B. Clinical validation of the Acuros XB photon dose calculation algorithm, a grid-based Boltzmann equation solver. Acta Oncol 2012; 51 (3): 376–385.10.3109/0284186X.2011.629209CrossRefGoogle ScholarPubMed
Fogliata, A, Nicolini, G, Clivio, A, Vanetti, E, Cozzi, L. Accuracy of Acuros XB and AAA dose calculation for small fields with reference to RapidArc(®) stereotactic treatments. Med Phys 2011; 38(11): 6228–6237.10.1118/1.3654739CrossRefGoogle ScholarPubMed
Lobo, J, Popescu, I. Two new DOSXYZnrc sources for 4D Monte Carlo simulations of continuously variable beam configurations, with applications to RapidArc, VMAT, TomoTherapy and CyberKnife. Phy Med Biol 2010; 55 (16): 4431–4474.10.1088/0031-9155/55/16/S01CrossRefGoogle ScholarPubMed
Mackie, T R, Khatib, E, Battista, J et al. Lung dose corrections for 6- and 15-MV x rays. Med Phys 1985; 12: 327–332.10.1118/1.595691CrossRefGoogle ScholarPubMed
White, D R, Booz, J, Griffith, R et al. Tissue substitutes in radiation dosimetry and measurement (Report 44). J Int Commission Radiat Units Meas 1989: 23 (1): 1–189.Google Scholar
Archambault, L, Beddar, A S, Gingras, L et al. Measurement accuracy and Cerenkov removal for high performance, high spatial resolution scintillation dosimetry. Med Phys 2006; 33: 128–135.10.1118/1.2138010CrossRefGoogle ScholarPubMed
Guillot, M, Gingras, L, Archambault, L et al. Spectral method for the correction of the Cerenkov light effect in plastic scintillation detectors: a comparison study of calibration procedures and validation in Cerenkov light-dominated situations. Med Phys 2011; 38: 2140–2150.10.1118/1.3562896CrossRefGoogle ScholarPubMed
Ralston, A, Liu, P, Warrener, K et al. Small field diode correction factors derived using an air core fiber optic scintillation dosimeter and EBT2 film. Phys Med Biol 2012; 57: 2587–2602.10.1088/0031-9155/57/9/2587CrossRefGoogle ScholarPubMed
Azangwe, G, Grochowska, P, Georg, D et al. Detector to detector corrections: a comprehensive experimental study of detector specific correction factors for beam output measurements for small radiotherapy beams. Med Phys 2014; 41: 072103-1–16.10.1118/1.4883795CrossRefGoogle ScholarPubMed
Wuerfel, J U. Dose measurements in small fields. Med Phy Int J 2013; 1: 81–90.Google Scholar
Zhen, H, Hrycushko, B, Lee, H et al. Dosimetric comparison of Acuros XB with collapsed cone convolution/superposition and anisotropic analytic algorithm for stereotactic ablative radiotherapy of thoracic spinal metastases. J Appl Clin Med Phy 2015; 16: 181–192.10.1120/jacmp.v16i4.5493CrossRefGoogle ScholarPubMed
Hirata, K, Nakamura, M, Yoshimura, M et al. Dosimetric evaluation of the Acuros XB algorithm for a 4MV photon beam in head and neck intensity-modulated radiation therapy. J Appl Clin Med Phy 2015; 16: 52–64.10.1120/jacmp.v16i4.5222CrossRefGoogle Scholar
Fogliata, A, Lobefalo, F, Reggiori, G et al. Evaluation of the dose calculation accuracy for small fields defined by jaw or MLC for AAA and Acuros XB algorithms. Med Phys 2016; 43(10): 5685–5694.10.1118/1.4963219CrossRefGoogle ScholarPubMed