Highlights
- •Monte Carlo computed clinical plans for the TomoTherapy system with dynamic jaws.
- •First Monte Carlo evaluation of TomoTherapy TPS with VoLO and TomoEdge.
- •Good agreement between MC and TomoTherapy's TPS (typically 1% for targets).
- •5% difference for small lung tumors, due to dose calculation, not TomoEdge model.
Abstract
Purpose
For the TomoTherapy® system, longitudinal conformation can be improved by selecting a smaller field width
but at the expense of longer treatment time. Recently, the TomoEdge® feature has been released with the possibility to move dynamically the jaws at the
edges of the target volume, improving longitudinal penumbra and enabling faster treatments.
Such delivery scheme requires additional modeling of treatment delivery. Using a previously
validated Monte Carlo model (TomoPen), we evaluated the accuracy of the implementation
of TomoEdge in the new dose engine of TomoTherapy for 15 clinical cases.
Methods
TomoPen is based on PENELOPE. Particle tracking in the treatment head is performed
almost instantaneously by 1) reading a particle from a phase-space file corresponding
to the largest field and 2) correcting the weight of the particle depending on the
actual jaw and MLC configurations using Monte Carlo pre-generated data. 15 clinical
plans (5 head-and-neck, 5 lung and 5 prostate tumors) planned with TomoEdge and with
the last release of the treatment planning system (VoLO®) were re-computed with TomoPen. The resulting dose-volume histograms were compared.
Results
Good agreement was achieved overall, with deviations for the target volumes typically
within 2% (D95), excepted for small lung tumors (17 cm3) where a maximum deviation of 4.4% was observed for D95. The results were consistent with previously reported values for static field widths.
Conclusions
For the clinical cases considered in the present study, the introduction of TomoEdge
did not impact significantly the accuracy of the computed dose distributions.
Keywords
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References
- History of tomotherapy.Phys Med Biol. 2006; 51: R427-R453
- Tomotherapy: a new concept in the delivery of dynamic conformal radiotherapy.Med Phys. 1993; 20: 1709-1719
- Dynamic tomotherapy delivery.Med Phys. 2011; 38: 3013-3024
- Dynamic jaws and dynamic couch in helical tomotherapy.Int J Radiat Oncol Biol Phys. 2010; 76: 1266-1273
- A non-voxel-based broad-beam (NVBB) framework for IMRT treatment planning.Phys Med Biol. 2010; 55: 7175-7210
- Ultrafast convolution/superposition using tabulated and exponential kernels on GPU.Med Phys. 2011; 38: 1150
- Validation of GPU based TomoTherapy dose calculation engine.Med Phys. 2012; 39: 1877-1886
- Monte Carlo evaluation of the convolution/superposition algorithm of Hi-ArtTM tomotherapy in heterogeneous phantoms and clinical cases.Med Phys. 2009; 36: 1566-1575
- Monte Carlo evaluation of a treatment planning system for helical tomotherapy in an anthropomorphic heterogeneous phantom and for clinical treatment plans.Med Phys. 2008; 35: 5366-5374https://doi.org/10.1118/1.3002316
- Monte Carlo simulation of helical tomotherapy with PENELOPE.Phys Med Biol. 2008; 53: 2161-2180https://doi.org/10.1088/0031-9155/53/8/011
- Monte Carlo-based simulation of dynamic jaws tomotherapy.Med Phys. 2011; 38: 5230-5238
- PENELOPE—A code system for monte carlo simulation of electron and photon transport.in: Workshop proceedings. OECD Nuclear Energy Agency, France2010
- Monte Carlo simulation of the tomotherapy treatment unit in the static mode using MC HAMMER, a Monte Carlo tool dedicated to Tomotherapy.J Phys Conf Ser. 2007; 74: 021019
- Analytical model of the binary multileaf collimator of tomotherapy for Monte Carlo simulations.J Phys Confer Ser. 2008; 102: 012022
- Monte Carlo-based analytical model for small and variable fields delivered by TomoTherapy.Radiother Oncol. 2010; 94: 229-234
- Impact of the number of discrete angles used during dose computation for TomoTherapy treatments.Med Phys. 2012; 39: 6947-6956
- Impact of the fixed gantry angle approximation on dosimetric accuracy for helical tomotherapy plans.Med Phys. 2013; 40: 011711https://doi.org/10.1118/1.4769120
- A dosimetric comparison of IMRT versus helical tomotherapy for brain tumors.Phys Medica. 2014; 30: 497-502
- Optimization of treatment planning parameters used in tomotherapy for prostate cancer patients.Phys Medica. 2013; 29: 273-285
- QA for helical tomotherapy: report of the AAPM Task Group 148.Med Phys. 2010; 37: 4817-4853
- Patient specific treatment verifications for helical tomotherapy treatment plans.Med Phys. 2005; 32: 3793https://doi.org/10.1118/1.2134929
- Evaluation of Gafchromic(®) EBT3 films characteristics in therapy photon, electron and proton beams.Phys Med. 2012; : 1-10https://doi.org/10.1016/j.ejmp.2012.10.001
- Dose to the skin in helical tomotherapy: results of in vivo measurements with radiochromic films.Phys Medica. 2013; 29: 304-311
- Dosimetric accuracy of tomotherapy dose calculation in thorax lesions.Radiat Oncol. 2011; 6 (10 pp): 14
- Dose calculations for external photon beams in radiotherapy.Phys Med Biol. 1999; 44: R99-R155
Article info
Publication history
Published online: February 03, 2015
Accepted:
January 19,
2015
Received in revised form:
January 14,
2015
Received:
December 10,
2014
Identification
Copyright
© 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Inc. All rights reserved.
