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Fourkal E , Li JS , Xiong W , Nahum A , Ma CM
Intensity modulated radiation therapy using laser-accelerated protons: a Monte Carlo dosimetric study
Physics in Medicine and Biology. 2003 Dec;48(24) :3977-4000
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Abstract
In this paper we present Monte Carlo studies of intensity modulated radiation therapy using laser-accelerated proton beams. Laser-accelerated protons coming out of a solid high-density target have broad energy and angular spectra leading to dose distributions that cannot be directly used for therapeutic applications. Through the introduction of a spectrometer-like particle selection system that delivers small pencil beams of protons with desired energy spectra it is feasible to use laser-accelerated protons for intensity modulated radiotherapy. The method presented in this paper is a three-dimensional modulation in which the proton energy spectrum and intensity of each individual beamlet are modulated to yield a homogeneous dose in both the longitudinal and lateral directions. As an evaluation of the efficacy of this method, it has been applied to two prostate cases using a variety of beam arrangements. We have performed a comparison study between intensity modulated photon ! plans and those for laser-accelerated protons. For identical beam arrangements and the same optimization parameters, proton plans exhibit superior coverage of the target and sparing of neighbouring critical structures. Dose-volume histogram analysis of the resulting dose distributions shows up to 50% reduction of dose to the critical structures. As the number of fields is decreased, the proton modality exhibits a better preservation of the optimization requirements on the target and critical structures. It is shown that for a two-beam arrangement (parallel-opposed) it is possible to achieve both superior target coverage with 5% dose inhomogeneity within the target and excellent sparing of surrounding tissue.
Notes
English Article KeyWords Plus: PROSTATE-CANCER; PLASMA INTERACTIONS; POTENTIAL ROLE; NORMAL TISSUE; BEAM THERAPY; HEAVY-ION; RADIOTHERAPY; IRRADIATION; GENERATION; PHOTONS Fourkal, E; *Fox* *Chase* Canc Ctr, Dept Radiat Oncol, 7701 Burholme Ave, Philadelphia, PA 19111 USA. Research Addresses: *Fox* *Chase* Canc Ctr, Dept Radiat Oncol, Philadelphia, PA 19111 USA. Cited References: ARCHAMBEAU JO, 1992, INT J RADIAT ONCOL, V22, P287 BIRDSALL CK, 1985, PLASMA PHYSICS COMPU BRAHME A, 1989, RADIOTHER ONCOL, V15, P189 BULANOV SV, 2000, JETP LETT+, V71, P407 BURMAN C, 1991, INT J RADIAT ONCOL, V21, P123 0031-9155