Assessment of Imprecise Small Photon Beam Modeling by Two Treatment Planning System Algorithms

Hadi Keivan, Daryoush Shahbazi-Gahrouei, Ahmad shanei, Alireza Amouheidari

DOI: 10.4103/jmss.JMSS_28_17

Abstract


Background: Dosimetric accuracy in intensity‑modulated radiation therapy (IMRT) is the
main part of quality assurance program. Improper beam modeling of small felds by treatment
planning system (TPS) can lead to inaccuracy in treatment delivery. This study aimed to evaluate
of the dose delivery accuracy at small segments of IMRT technique using two‑dimensional (2D)
array as well as evaluate the capability of two TPSs algorithm in modeling of small felds.
Materials and Methods: Irradiation were performed using 6 MV photon beam of Siemens Artiste
linear accelerator. Dosimetric behaviors of two dose calculation algorithms, namely, collapsed cone
convolution/superposition (CCCS) and full scatter convolution (FSC) in small segments of IMRT
plans were analyzed using a 2D diode array and gamma evaluation. Results: Comparisons of
measurements against TPSs calculations showed that percentage difference of output factors of small
felds were 2% and 15% for CCCS and FSC algorithm, respectively. Gamma analysis of calculated
dose distributions by TPSs against those measured by 2D array showed that in passing criteria of
3 mm/3%, the mean pass rate for all segment sizes is higher than 95% except for segment sizes
below 3 cm × 3 cm optimized by TiGRT TPS. Conclusions: High pass rate of gamma index (95%)
achieved in planned small segments by Prowess relative to results obtained with TiGRT. This study
showed that the accuracy of small feld modeling differs between two dose calculation algorithms.

Keywords


Dose calculation algorithm, small‑intensity modulated radiation therapy segment, two‑dimensional array

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References


Karbalaee M, Shahbazi-Gahrouei D, Tavakoli MB. An approach in radiation therapy treatment planning: A fast, GPU-based monte carlo method. J Med Signals Sens 2017;7:108-13.

Webb S. Intensity-Modulated Radiation Therapy. Philadelphia, USA: CRC Press; 2015.

Cedric XY, Li XA, Ma L, Chen D, Naqvi S, Shepard D, et al. Clinical implementation of intensity-modulated arc therapy. Int J Radiat Oncol Biol Phys 2002;53:453-63.

Rezaee V, Shahbazi-Gahrouei D, Monadi S, Saeb M. Evaluation of error doses of treatment planning software using solid anthropomorphic phantom. J Isfahan Med Sch 2016;34:908-13.

Zeidan OA, Stephenson SA, Meeks SL, Wagner TH, Willoughby TR, Kupelian PA, et al. Characterization and use of EBT radiochromic fi lm for IMRT dose verifi cation. Med Phys 2006;33:4064-72.

Casanova Borca V, Pasquino M, Russo G, Grosso P, Cante D, Sciacero P, et al. Dosimetric characterization and use of GAFCHROMIC EBT3 fi lm for IMRT dose verifi cation. J Appl Clin Med Phys 2013;14:4111.

Sorriaux J, Kacperek A, Rossomme S, Lee JA, Bertrand D, Vynckier S, et al. Evaluation of gafchromic EBT3 fi lms characteristics in therapy photon, electron and proton beams. Phys Med 2013;29:599-606.

Mosleh-Shirazi MA, Karbasi S, Shahbazi-Gahrouei D, Monadi S. A monte carlo and experimental investigation of the dosimetric behavior of low-and medium-perturbation diodes used for entrance in vivo dosimetry in megavoltage photon beams. J Appl Clin Med Phys 2012;13:3917.

Letourneau D, Gulam M, Yan D, Oldham M, Wong JW. Evaluation of a 2D diode array for IMRT quality assurance. Radiother Oncol 2004;70:199-206.

Van Esch A, Clermont C, Devillers M, Iori M, Huyskens DP. On-line quality assurance of rotational radiotherapy treatment delivery by means of a 2D ion chamber array and the Octavius phantom. Med Phys 2007;34:3825-37.

Wagner D, Vorwerk H. Two years experience with quality assurance protocol for patient related rapid arc treatment plan verifi cation using a two dimensional ionization chamber array. Radiat Oncol 2011;6:21.

Syamkumar SA, Padmanabhan S, Sukumar P, Nagarajan V. Characterization of responses of 2d array seven29 detector and its combined use with octavius phantom for the patient-specifi c quality assurance in rapidarc treatment delivery. Med Dosim 2012;37:53-60.

Boggula R, Birkner M, Lohr F, Steil V, Wenz F, Wertz H, et al. Evaluation of a 2D detector array for patient-specifi c VMAT QA with different setups. Phys Med Biol 2011;56:7163-77.

Poppe B, Stelljes TS, Looe HK, Chofor N, Harder D, Willborn K, et al. Performance parameters of a liquid fi lled ionization chamber array. Med Phys 2013;40:082106.

Das IJ, Ding GX, Ahnesjö A. Small fi elds: Nonequilibrium radiation dosimetry. Med Phys 2008;35:206-15.

Bouchard H, Seuntjens J, Duane S, Kamio Y, Palmans H. Detector dose response in megavoltage small photon beams. I. Theoretical concepts. Med Phys 2015;42:6033-47.

Aspradakis MM, Lambert GD, Steele A. Elements of commissioning step-and-shoot IMRT: Delivery equipment and planning system issues posed by small segment dimensions and small monitor units. Med Dosim 2005;30:233-42.

Azangwe G, Grochowska P, Georg D, Izewska J, Hopfgartner J, Lechner W, 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.

Derreumaux S, Etard C, Huet C, Trompier F, Clairand I, Bottollier-Depois JF, et al. Lessons from recent accidents in radiation therapy in France. Radiat Prot Dosimetry 2008;131:130-5.

Martens C, De Wagter C, De Neve W. The value of the pinPoint ion chamber for characterization of small fi eld segments used in intensity-modulated radiotherapy. Phys Med Biol 2000;45:2519-30.

Shin HJ, Kim MH, Choi IB, Kang YN, Kim DH, Chio BO, et al. Evaluation of the EDGE detector in small-fi eld dosimetry. J Korean Phys Soc 2013;63:128-34.

Ahnesjo A. Collapsed cone convolution of radiant energy for photon dose calculation in heterogeneous media. Med Phys 1989;16:577-92.

Low DA, Harms WB, Mutic S, Purdy JA. A technique for the quantitative evaluation of dose distributions. Med Phys 1998;25:656-61.

Ezzell GA, Burmeister JW, Dogan N, LoSasso TJ, Mechalakos JG, Mihailidis D, et al. IMRT commissioning: Multiple institution planning and dosimetry comparisons, a report from AAPM task group 119. Med Phys 2009;36:5359-73.

Jin H, Keeling V, Ahmad S. SU-E-T-74: Effect of energy and fi eld size on angular dependence of a 2D diode array. Med Phys 2013;40:220.

Jursinic PA, Sharma R, Reuter J. MapCHECK used for rotational IMRT measurements: Step-and-shoot, tomotherapy, RapidArc. Med Phys 2010;37:2837-46.

Alber M, Broggi S, De Wagter C, Eichwurzel I, Engstrom P, Fiorino C, et al. Guidelines for the Verifi cation of IMRT. ESTRO Booklet; 2008. p. 7.

Bassinet C, Huet C, Derreumaux S, Brunet G, Chea M Baumann M, et al. Small fields output factors measurements and correction factors determination for several detectors for a CyberKnife and linear accelerators equipped with microMLC and circular cones. Med Phys 2013;40:071725.

Fogliata A, Vanetti E, Albers D, Brink C, Clivio A, Knoos T, 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 Biol 2007;52:1363-85.

Knoos T, Wieslander E, Cozzi L, Brink C, Fogliata A, Albers D, et al. Comparison of dose calculation algorithms for treatment planning in external photon beam therapy for clinical situations. Phys Med Biol 2006;51:5785-807.

Rana S, Rogers K, Pokharel S, Cheng C. Evaluation of acuros XB algorithm based on RTOG 0813 dosimetric criteria for SBRT lung treatment with rapidArc. J Appl Clin Med Phys 2014;15:4474.

Fogliata A, Cozzi L. Dose calculation algorithm accuracy for small fi elds in non-homogeneous media: The lung SBRT case. Phys Med 2016. pii: S1120-1797(16)30988-7.

Hasenbalg F, Neuenschwander H, Mini R, Born EJ. Collapsed cone convolution and analytical anisotropic algorithm dose calculations compared to VMC++ monte carlo simulations in clinical cases. Phys Med Biol 2007;52:3679-91.

Carrasco P, Jornet N, Duch MA, Weber L, Ginjaume M, Eudaldo T, et al. Comparison of dose calculation algorithms in phantoms with lung equivalent heterogeneities under conditions of lateral electronic disequilibrium. Med Phys 2004;31:2899-911.

Shalek RJ. Determination of absorbed dose in a patient irradiated by beams of X or gamma rays in radiotherapy procedures. Med Phys 1977;4:461.


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