Harald Paganetti1. 1. Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA. hpaganetti@partners.org
Abstract
The main advantages of proton therapy are the reduced total energy deposited in the patient as compared to photon techniques and the finite range of the proton beam. The latter adds an additional degree of freedom to treatment planning. The range in tissue is associated with considerable uncertainties caused by imaging, patient setup, beam delivery and dose calculation. Reducing the uncertainties would allow a reduction of the treatment volume and thus allow a better utilization of the advantages of protons. This paper summarizes the role of Monte Carlo simulations when aiming at a reduction of range uncertainties in proton therapy. Differences in dose calculation when comparing Monte Carlo with analytical algorithms are analyzed as well as range uncertainties due to material constants and CT conversion. Range uncertainties due to biological effects and the role of Monte Carlo for in vivo range verification are discussed. Furthermore, the current range uncertainty recipes used at several proton therapy facilities are revisited. We conclude that a significant impact of Monte Carlo dose calculation can be expected in complex geometries where local range uncertainties due to multiple Coulomb scattering will reduce the accuracy of analytical algorithms. In these cases Monte Carlo techniques might reduce the range uncertainty by several mm.
The main advantages of proton therapy are the reduced total energy deposited in the n class="Species">patient as compared to photon techniques and the finite range of the proton beam. The latter adds an additional degree of freedom to treatment planning. The range in tissue is associated with considerable uncertainties caused by imaging, patient setup, beam delivery and dose calculation. Reducing the uncertainties would allow a reduction of the treatment volume and thus allow a better utilization of the advantages of protons. This paper summarizes the role of Monte Carlo simulations when aiming at a reduction of range uncertainties in proton therapy. Differences in dose calculation when comparing Monte Carlo with analytical algorithms are analyzed as well as range uncertainties due to material constants and CT conversion. Range uncertainties due to biological effects and the role of Monte Carlo for in vivo range verification are discussed. Furthermore, the current range uncertainty recipes used at several proton therapy facilities are revisited. We conclude that a significant impact of Monte Carlo dose calculation can be expected in complex geometries where local range uncertainties due to multiple Coulomb scattering will reduce the accuracy of analytical algorithms. In these cases Monte Carlo techniques might reduce the range uncertainty by several mm.
Authors: Michael F Gensheimer; Torunn I Yock; Norbert J Liebsch; Gregory C Sharp; Harald Paganetti; Neel Madan; P Ellen Grant; Thomas Bortfeld Journal: Int J Radiat Oncol Biol Phys Date: 2010-05-17 Impact factor: 7.038
Authors: Nan Qin; Marco Pinto; Zhen Tian; Georgios Dedes; Arnold Pompos; Steve B Jiang; Katia Parodi; Xun Jia Journal: Phys Med Biol Date: 2017-01-31 Impact factor: 3.609
Authors: Pierluigi Piersimoni; Bruce A Faddegon; José Ramos Méndez; Reinhard W Schulte; Lennart Volz; Joao Seco Journal: Med Phys Date: 2018-05-20 Impact factor: 4.071
Authors: Martin T King; Laszlo Voros; Gil'ad N Cohen; Ryan M Lanning; Ian Ganly; Chibuzo C O'Suoji; Suzanne L Wolden Journal: Brachytherapy Date: 2016-08-12 Impact factor: 2.362
Authors: Kira Grogg; Xuping Zhu; Chul Hee Min; Brian Winey; Thomas Bortfeld; Harald Paganetti; Helen A Shih; Georges El Fakhri Journal: IEEE Trans Nucl Sci Date: 2013-10 Impact factor: 1.679