Intensity modulated proton therapy and its sensitivity to treatment uncertainties 1: the potential effects of calculational uncertainties
- 29 January 2008
- journal article
- Published by IOP Publishing in Physics in Medicine & Biology
- Vol. 53 (4), 1027-1042
- https://doi.org/10.1088/0031-9155/53/4/014
Abstract
The effects of calculational uncertainties on 3D and distal edge tracking (DET) intensity modulated proton therapy (IMPT) treatment plans have been investigated. Dose calculation uncertainties have been assessed by comparing analytical and Monte Carlo dose calculations, and potential range uncertainties by recalculating plans with all CT values modified by +/-3%. Analysis of the volume of PTV agreeing to within +/-3% between the two calculations shows that the 3D approach provides significantly improved agreement (87.1 versus 80.3% of points for the 3D and DET approaches, respectively). For the DET approach, doses in the CTV have also been found to globally change by 5% as a result of 3% changes in CT value. When varying the intra-field gradients of the plans a similar trend is seen, but with the more complex plans also being found to be more sensitive to both uncertainties. In conclusion, the DET approach has been found to be relatively sensitive to the calculational errors investigated here. In contrast, the 3D approach appears to be quite robust, unless strong internal gradients are present. Nevertheless, the routine use of uncertainty analysis is advised when assessing all forms of IMPT plans.Keywords
This publication has 41 references indexed in Scilit:
- The influence of beam model differences in the comparison of dose calculation algorithms for lung cancer treatment planningPhysics in Medicine & Biology, 2005
- Adaptation of GEANT4 to Monte Carlo dose calculations based on CT dataMedical Physics, 2004
- Accounting for center‐of‐mass target motion using convolution methods in Monte Carlo‐based dose calculations of the lungMedical Physics, 2004
- The dosimetric consequences of inter-fractional patient movement on three classes of intensity-modulated delivery techniques in breast radiotherapy.Radiotherapy and Oncology, 2001
- A simulation of the effects of set-up error and changes in breast volume on conventional and intensity-modulated treatments in breast radiotherapyPhysics in Medicine & Biology, 2001
- A proton dose calculation algorithm for conformal therapy simulations based on Molière's theory of lateral deflectionsMedical Physics, 1998
- Target margins for random geometrical treatment uncertainties in conformal radiotherapyMedical Physics, 1996
- Calculation of the uncertainty in the dose delivered during radiation therapyMedical Physics, 1985
- Measurements and calculations of the influence of thin inhomogeneities on charged particle beamsMedical Physics, 1978
- A technique for calculating the influence of thin inhomogeneities on charged particle beamsMedical Physics, 1978