A technology platform for translational research on laser driven particle accelerators for radiotherapy
05 May 2011-Proceedings of SPIE (International Society for Optics and Photonics)-Vol. 8079, pp 177-184
TL;DR: In this paper, a new facility for translational research on the campus of the university hospital Dresden is proposed, which will be connected to the department of radiooncology and host a petawatt laser system delivering an experimental proton and a conventional therapeutic proton cyclotron.
Abstract: It is widely accepted that proton or light ion beams may have a high potential for improving cancer cure by means of
radiation therapy. However, at present the large dimensions of electromagnetic accelerators prevent particle therapy from
being clinically introduced on a broad scale. Therefore, several technological approaches among them laser driven particle
acceleration are under investigation.
Parallel to the development of suitable high intensity lasers, research is necessary to transfer laser accelerated particle
beams to radiotherapy, since the relevant parameters of laser driven particle beams dramatically differ from those of
beams delivered by conventional accelerators: The duty cycle is low, whereas the number of particles and thus the dose
rate per pulse are high. Laser accelerated particle beams show a broad energy spectrum and substantial intensity fluctuations
from pulse to pulse. These properties may influence the biological efficiency and they require completely new
techniques of beam delivery and quality assurance.
For this translational research a new facility is currently constructed on the campus of the university hospital Dresden. It
will be connected to the department of radiooncology and host a petawatt laser system delivering an experimental proton
beam and a conventional therapeutic proton cyclotron. The cyclotron beam will be delivered on the one hand to an isocentric
gantry for patient treatments and on the other hand to an experimental irradiation site. This way the conventional
accelerator will deliver a reference beam for all steps of developing the laser based technology towards clinical applicability.
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TL;DR: An overview of the state of the art of ion acceleration by laser pulses as well as an outlook on its future development and perspectives are given in this article. But the main features observed in the experiments, the observed scaling with laser and plasma parameters, and the main models used both to interpret experimental data and to suggest new research directions are described.
Abstract: Ion acceleration driven by superintense laser pulses is attracting an impressive and steadily increasing effort. Motivations can be found in the applicative potential and in the perspective to investigate novel regimes as available laser intensities will be increasing. Experiments have demonstrated, over a wide range of laser and target parameters, the generation of multi-MeV proton and ion beams with unique properties such as ultrashort duration, high brilliance, and low emittance. An overview is given of the state of the art of ion acceleration by laser pulses as well as an outlook on its future development and perspectives. The main features observed in the experiments, the observed scaling with laser and plasma parameters, and the main models used both to interpret experimental data and to suggest new research directions are described.
1,221 citations
19 Mar 2008
TL;DR: Heavy-charged particle therapy has now come into a consolidation phase and hospital-based facilities are built by industry, and research institutes focus on refinements in dose delivery and treatment planning, as well as systems for monitoring dose Delivery and for dose distribution verification.
Abstract: Nuclear science has contributed significantly to the development of tumor therapy with heavy charged particles. Interest evolved for neutron therapies in the forties because of the increased radiobiological effectiveness (RBE) compared to photon irradiation. The development of more powerful proton and heavy ion accelerators with higher energies or higher intensities, made new particles for radiation therapy available. Pions, protons, light ions, from helium up to silicon were studied in view of precision dose delivery and increased RBE. Without the parallel development of new diagnostic techniques such as computer tomography (CT) and positron emission tomography (PET) the rapid development would not have been possible. Heavy-charged particle therapy has now come into a consolidation phase. Hospital-based facilities are built by industry, and research institutes focus on refinements in dose delivery and treatment planning, as well as systems for monitoring dose delivery and for dose distribution verification.
159 citations
Posted Content•
TL;DR: In this article, the authors demonstrated the achievable energy of laser-accelerated proton and ion beams to energies exceeding 150 MeV, reaching the therapy window, using a diferent acceleration regime rather than a larger laser.
Abstract: Proton (and ion) cancer therapy has proven to be an extremely effective even supe-rior method of treatment for some tumors 1-4. A major problem, however, lies in the cost of the particle accelerator facilities; high procurement costs severely limit the availability of ion radiation therapy, with only ~26 centers worldwide. Moreover, high operating costs often prevent economic operation without state subsidies and have led to a shutdown of existing facilities 5,6. Laser-accelerated proton and ion beams have long been thought of as a way out of this dilemma, with the potential to provide the required ion beams at lower cost and smaller facility footprint 7-14. The biggest challenge has been the achievement of sufficient particle energy for therapy, in the 150-250 MeV range for protons 15,16. For the last decade, the maximum exper-imentally observed energy of laser-accelerated protons has remained at ~60 MeV 17. Here we the experimental demonstration of laser-accelerated protons to energies exceeding 150 MeV, reaching the therapy window. This was achieved through a dif-ferent acceleration regime rather than a larger laser, specifically a 150 TW laser with CH2 nano-targets in the relativistically transparent regime 18,19. We also demonstrate a clear scaling law with laser intensity based on analytical theory, computer simulations and experimental validation that will enable design of a pro-totype system spanning the full range of therapeutically desirable energies.
22 citations
TL;DR: A small animal tumour model suitable for the irradiation with low energy particles was established and validated at a laser based particle accelerator, allowing a broader preclinical validation of radiobiological characteristics and efficacy of laser driven particle accelerators in the future.
Abstract: Background: The long-term aim of developing a laser based acceleration of protons and ions towards clinical application requires not only substantial technological progress, but also the radiobiological characterization of the resulting ultra-short pulsed particle beams. Recent in vitro data showed similar effects of laser-accelerated versus “conventional” protons on clonogenic cell survival. As the proton energies currently achieved by laser driven acceleration are too low to penetrate standard tumour models on mouse legs, the aim of the present work was to establish a tumour model allowing for the penetration of low energy protons (~ 20 MeV) to further verify their effects in vivo. Methods: KHT mouse sarcoma cells were injected subcutaneously in the right ear of NMRI (nu/nu) mice and the growing tumours were characterized with respect to growth parameters, histology and radiation response. In parallel, the laser system JETI was prepared for animal experimentation, i.e. a new irradiation setup was implemented and the laser parameters were carefully adjusted. Finally, a proof-of-principle experiment with laser accelerated electrons was performed to validate the tumour model under realistic conditions, i.e. altered environment and horizontal beam delivery. Results: KHT sarcoma on mice ears showed a high take rate and continuous tumour growth after reaching a volume of ~ 5 mm 3 . The first irradiation experiment using laser accelerated electrons versus 200 kV X-rays was successfully performed and tumour growth delay was evaluated. Comparable tumour growth delay was found between X-ray and laser accelerated electron irradiation. Moreover, experimental influences, like anaesthesia and positioning at JETI, were found to be negligible. Conclusion: A small animal tumour model suitable for the irradiation with low energy particles was established and validated at a laser based particle accelerator. Thus, the translation from in vitro to in vivo experimentation was for the first time realized allowing a broader preclinical validation of radiobiological characteristics and efficacy of laser driven particle accelerators in the future.
21 citations
Cites background from "A technology platform for translati..."
...As one potential alternative to the classical electromagnetic accelerators, particle acceleration by means of high intensity laser is under investigation [1,2]....
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01 Jan 2016
TL;DR: A summary of the state of the art in laser-driven ion acceleration, of the main challenges currently faced by the research in this field and of some of the current and future strategies for overcoming them is given in this paper.
Abstract: Laser-plasma based accelerators of protons and heavier ions are a source of potential interest for several applications, including in the biomedical area. While the potential future use in cancer hadrontherapy acts as a strong aspirational motivation for this research field, radiobiology employing laser-driven ion bursts is already an active field of research. Here we give a summary of the state of the art in laser-driven ion acceleration, of the main challenges currently faced by the research in this field and of some of the current and future strategies for overcoming them.
11 citations
References
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TL;DR: This work presents a novel aperture-based algorithm for treatment plan optimization where dose is delivered during a single gantry arc of up to 360 deg, similar to tomotherapy but fundamentally different in that the entire dose volume is delivered in a single source rotation.
Abstract: In this work a novel plan optimization platform is presented where treatment is delivered efficiently and accurately in a single dynamically modulated arc. Improvements in patient care achieved through image-guided positioning and plan adaptation have resulted in an increase in overall treatment times. Intensity-modulated radiation therapy(IMRT) has also increased treatment time by requiring a larger number of beam directions, increased monitor units (MU), and, in the case of tomotherapy, a slice-by-slice delivery. In order to maintain a similar level of patient throughput it will be necessary to increase the efficiency of treatmentdelivery. The solution proposed here is a novel aperture-based algorithm for treatment plan optimization where dose is delivered during a single gantry arc of up to 360 deg. The technique is similar to tomotherapy in that a full 360 deg of beam directions are available for optimization but is fundamentally different in that the entire dose volume is delivered in a single source rotation. The new technique is referred to as volumetric modulated arc therapy (VMAT). Multileaf collimator(MLC) leaf motion and number of MU per degree of gantry rotation is restricted during the optimization so that gantry rotation speed, leaf translation speed, and dose rate maxima do not excessively limit the delivery efficiency. During planning, investigators model continuous gantry motion by a coarse sampling of static gantry positions and fluence maps or MLC aperture shapes. The technique presented here is unique in that gantry and MLC position sampling is progressively increased throughout the optimization. Using the full gantry range will theoretically provide increased flexibility in generating highly conformal treatment plans. In practice, the additional flexibility is somewhat negated by the additional constraints placed on the amount of MLC leaf motion between gantry samples. A series of studies are performed that characterize the relationship between gantry and MLC sampling, dose modeling accuracy, and optimization time. Results show that gantry angle and MLC sample spacing as low as 1 deg and 0.5 cm, respectively, is desirable for accurate dose modeling. It is also shown that reducing the sample spacing dramatically reduces the ability of the optimization to arrive at a solution. The competing benefits of having small and large sample spacing are mutually realized using the progressive sampling technique described here. Preliminary results show that plans generated with VMAT optimization exhibit dose distributions equivalent or superior to static gantry IMRT. Timing studies have shown that the VMAT technique is well suited for on-line verification and adaptation with delivery times that are reduced to ∼ 1.5 – 3 min for a 200 cGy fraction.
1,698 citations
TL;DR: An intense collimated beam of high-energy protons is emitted normal to the rear surface of thin solid targets irradiated at 1 PW power and peak intensity 3x10(20) W cm(-2).
Abstract: An intense collimated beam of high-energy protons is emitted normal to the rear surface of thin solid targets irradiated at 1 PW power and peak intensity 3x10(20) W cm(-2). Up to 48 J ( 12%) of the laser energy is transferred to 2x10(13) protons of energy >10 MeV. The energy spectrum exhibits a sharp high-energy cutoff as high as 58 MeV on the axis of the beam which decreases in energy with increasing off axis angle. Proton induced nuclear processes have been observed and used to characterize the beam.
1,496 citations
TL;DR: In the scheme proposed, a beam of fast ions accelerated by a laser pulse can be integrated in the installations intended for proton therapy, ensuring that the irradiation of the surrounding healthy tissues and organs is minimal.
Abstract: The feasibility of using laser plasma as a source of high-energy ions for the purposes of proton therapy is discussed The proposal is based on the efficient ion acceleration observed in recent laboratory and numerical experiments on the interaction of high-power laser radiation with gaseous and solid targets The specific dependence of proton energy losses in biological tissues (the Bragg peak) promotes the solution of one of the main problems of radiation therapy, namely, the irradiation of a malignant tumor with a sufficiently strong and homogeneous dose, ensuring that the irradiation of the surrounding healthy tissues and organs is minimal In the scheme proposed, a beam of fast ions accelerated by a laser pulse can be integrated in the installations intended for proton therapy
477 citations
TL;DR: A multilayered collimator system has been constructed as a practical means to locate the dose ends by measuring prompt gammas and clearly indicated correlations between the gamma distributions and the distal falloff regions.
Abstract: The location of the distal falloff in the proton therapy is an important but often uncertain parameter as different tissue elements are traversed by the beam. A multilayered collimator system has been constructed as a practical means to locate the dose ends by measuring prompt gammas. The collimator is designed to moderate and capture fast neutrons and to prevent unwanted gammas from reaching the scintillation detector. The system has been studied using Monte Carlo technique and has been tested in the beam energy range of 100–200MeV. Measurements clearly indicated correlations between the gamma distributions and the distal falloff regions.
426 citations
TL;DR: In this paper, the first in-beam PET measurements of the beta+ activation induced by proton irradiation are presented, which supports the feasibility of an in- situ proton therapy monitoring by means of PET, as already clinically implemented for the monitoring of carbon ion therapy at GSI Darmstadt.
Abstract: Our first in-beam PET measurements of the beta+ activation induced by proton irradiation are presented. Monoenergetic proton beams in the energy and intensity range suited for the treatment of deep-seated tumours were delivered by the synchrotron of the Gesellschaft fur Schwerionenforschung Darmstadt (GSI). They were stopped in PMMA blocks placed in the centre of the field of view of the positron camera that is installed in the heavy ion tumour treatment facility at GSI. The beta+ activity signal was found to be three times larger than that produced by carbon ions at the same range and applied physical dose. The reconstructed spatial beta+ activity distributions were analysed and compared with the production of positron emitters predicted by a calculation based on experimental cross-sections and on the proton flux given by the FLUKA Monte Carlo code. The shape of the depth-activity profiles was well reproduced by the model and the correlation with the proton range and the depth-dose distributions was carefully investigated. Despite the non-trivial range determination from the beta+ activity distribution in the proton case, our experimental investigation supports the feasibility of an in situ proton therapy monitoring by means of in-beam PET, as already clinically implemented for the monitoring of carbon ion therapy at GSI Darmstadt.
237 citations