A5061218448- Radiation Therapy and Dosimetry
- Advanced Radiotherapy Techniques
- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Radiation Detection and Scintillator Technologies
- Quantum Chromodynamics and Particle Interactions
- Radiation Effects in Electronics
- Particle accelerators and beam dynamics
- Nuclear Physics and Applications
- Particle Accelerators and Free-Electron Lasers
- Particle Detector Development and Performance
- Spacecraft and Cryogenic Technologies
- Photocathodes and Microchannel Plates
- Atomic and Subatomic Physics Research
- Radiation Effects and Dosimetry
- Advanced Thermodynamic Systems and Engines
- Medical Imaging Techniques and Applications
- Nuclear reactor physics and engineering
- Superconducting Materials and Applications
- Dark Matter and Cosmic Phenomena
- Boron Compounds in Chemistry
- Radiomics and Machine Learning in Medical Imaging
- Cosmology and Gravitation Theories
- Systemic Sclerosis and Related Diseases
- Food composition and properties
Paul Scherrer Institute
2015-2024
Emory University
2022-2024
University Hospital of Zurich
2018
University of Groningen
2016
Sest (United States)
2009-2012
Delft University of Technology
2008
Swiss National Science Foundation
2002-2006
ETH Zurich
2001-2006
Lund University
2001-2005
Joint Institute for Nuclear Research
2001-2005
Treating moving targets using a scanning gantry for proton therapy is promising but very challenging, not yet clinically demonstrated treatment modality. The interference of organ motion with the sequence beam delivery produces uncontrolled dose inhomogeneities within target. One approach to overcome this difficulty increase speed in order apply repeatedly (so-called repainting). To obtain sufficiently high speeds new, technologically improved gantry—Gantry 2—has been designed and currently...
Abstract Nanoparticle-based radioenhancement is a promising strategy for extending the therapeutic ratio of radiotherapy. While (pre)clinical results are encouraging, sound mechanistic understanding nanoparticle radioenhancement, especially effects nanomaterial selection and irradiation conditions, has yet to be achieved. Here, we investigate mechanisms selected metal oxide nanomaterials (including SiO 2 , TiO WO 3 HfO ), TiN Au nanoparticles radiotherapy utilizing photons (150 kVp 6 MV) 100...
The response of Al2O3:C optically stimulated luminescence detectors (OSLDs) was investigated in a 250 MeV pencil proton beam. OSLD mapped for wide range average dose rates up to 9000 Gy s-1, corresponding ∼150 kGy s-1instantaneous rate each pulse. Two setups ultra-high (FLASH) experiments are presented, which enable OSLDs or biological samples be irradiated either water-filled vials cylinders. were found independent all rates, with an deviation <1% relative the nominal (1-1000) s-1when two...
Purpose: The purpose of this work was to provide a flexible platform for FLASH research with protons by adapting former clinical pencil beam scanning gantry irradiations ultrahigh dose rates. Methods: PSI Gantry 1 treated patients until December 2018. We optimized the beamline parameters transport 250 MeV extracted from COMET accelerator treatment room, maximizing transmission intensity sample. characterized monitor on ensure good control dose, delivered in spot-scanning mode. different...
The physico-chemical and biological response to conventional UHDR electron proton beams was investigated, along with photons. temporal structure nature of the beam affected both, at ≥1400 Gy/s 0.1 1260 found be isoefficient sparing zebrafish embryos.
The FLASH effect has been validated in different preclinical experiments with electrons (eFLASH) and protons (pFLASH) operating at an average dose rate above 40 Gy/s. However, no systematic intercomparison of the produced by eFLASHvs. pFLASH yet performed constitutes aim present study.
In order to be able treat mobile tumours with active, scanned proton therapy, adequate motion mitigation techniques have applied. Re-scanning is such an approach, where the interplay effect between tumour and treatment delivery statistically smeared out. Different re-scanning methods been used for irradiation of a spherical target volume amplitudes up 10 mm. The resulting dose distributions captured in two dimensions by imaging scintillating screen at iso-centre different starting phases....
In this report we present the technical features of Gantry 2, new second generation scanning system PSI. On basis experience and success with first prototype, 1, built in 90s for introducing pencil beam IMPT into field proton therapy, have recently implemented a capable offering much faster repainted conformal being able to treat moving targets under image guidance, next challenge therapy. The developments are conducted parallel ongoing basic commissioning which should go operation usual...
The first goal of this paper is to clarify the reference conditions for dosimetry clinical proton beams. A clear distinction made between beam delivery systems which should be calibrated with a spread-out Bragg peak field and those that (pseudo-)monoenergetic beam. For latter, also compares two independent techniques calibrate monitor chambers: absolute (of number protons exiting nozzle) Faraday cup (i.e. determination absorbed dose water under IAEA TRS-398 conditions) an ionization chamber....
Organ motion is one of the major obstacles in radiotherapy and charged particle therapy. Even more so, theoretical advantages dose distributions scanned ion beam therapy may be lost due to interplay between organ scanning. Several techniques for dealing with this problem have been devised. In re-scanning, target volume several times average out effects. gating breath-hold, only delivered if tumour a narrow window position. Experiments performed verify re-scanning are effective means...
There are several general recommendations for quality assurance (QA) measures, which have to be performed at proton therapy centres. However, almost each centre uses a different system. In particular, there is no standard procedure centres employing pencil beam scanning and applies specific QA program. Gantry 2 an operating system was developed PSI relies on the most advanced technological innovations. We comprehensive daily program in order verify main characteristics assure functionality...
When using superconducting (SC) magnets in a gantry for proton therapy, the will benefit from some reduction size and large weight. In this contribution we show an important additional advantage of SC therapy treatments. We present design with bending section achromatic beam optics very momentum acceptance [Formula: see text]15% (corresponding to about text]30% energy domain). Due related acceptance, approximately 70% treatments can be performed without changing magnetic field...
Abstract In recent years, there has been a considerable push towards ultrahigh dose rates in proton therapy to effectively utilize motion mitigation strategies and potentially increase the sparing of healthy tissue through so-called FLASH effect. However, cyclotron-based facilities, it is difficult reach for low-energy beams. The main reason this lies large momentum spread that such beams have after reducing their energy levels required therapy, incurring losses conventionally used or...
Therapeutic pencil beams are typically scanned using one of the following three techniques: spot scanning, raster scanning or line scanning. While providing similar dose distributions to target, these techniques can differ significantly in their delivery time sequence. Thus, we expect differences effectiveness and efficiency when trying mitigate interplay effects rescanning. At Paul Scherrer Institute, able irradiate treatment plans either techniques. Hence, compare them directly with...
Mitigation of organ motion in active, scanning proton therapy is a challenge. One the easiest methods to implement re-scanning, where treatment plan applied several times with accordingly smaller weights. As consequence, effects are averaged out. For discrete spot scanning, major drawback this method time, which increases linearly number re-scans. Continuous line on other hand, eliminates dead time between positioning each beam, and work, continuous has been investigated experimentally from...
The use of motion mitigation techniques such as breath-hold can reduce the dosimetric uncertainty lung cancer proton therapy. We studied feasibility pencil beam scanning (PBS) therapy field delivery within a single at PSI's Gantry 2.In PBS therapy, time for is determined by beam-on and dead between spots (the required to change energy and/or lateral position). ways time, without sacrificing plan quality, aiming 15 seconds maximum. tested this approach on 10 cases with varying target volumes....
Circles of a single size can pack together densely in hexagonal lattice, but adding variety disrupts the order those packings. We conduct simulations which generate dense random packings circles with specified distributions and measure area fraction each case. While be arbitrary, we find that for wide range close-packing ϕ_{rcp} under this general protocol is determined to high accuracy by polydispersity skewness distribution. At low skewness, all tend minimum packing ϕ_{0}≈0.840 independent...
After 2001 the upgraded ep collider HERA will provide an about five times higher luminosity for two experiments H1 and ZEUS. In order to cope with expected event rates collaboration is building a track based trigger system, Fast Track Trigger (FTT). It be integrated in first three levels (L1-L3) of scheme selectivity events charged particles. The FTT allow reconstruct 3-dimensional tracks central drift chamber down 100 MeV/c within L2 latency ~ 23 mus. To reach necessary momentum resolution...
This paper provides an overview of the current developments in superconducting magnets for applications proton and ion therapy. It summarizes benefits challenges regarding utilization these accelerating systems (e.g. cyclotrons) gantries. The also examples currently used particle therapy proposed designs.
An on-line beam position monitoring and regular stability tests are of utmost importance for the Quality Assurance (QA) patient treatment at any particle therapy facility. The Gantry 2 Paul Scherrer Institute uses a strip ionization chamber verification. design placed in front allows small penumbra order to achieve high-quality lateral delivery. error 1 mm plane (plane perpendicular direction) can result dose inhomogeneity more than 5%. Therefore goal commissioning was reach sub-millimeter...
Recently, proton therapy treatments delivered with ultra-high dose rates have been of high scientific interest, and the Faraday cup (FC) is a promising dosimetry tool for such experiments. Different institutes use different FC designs, either voltage guard ring, or combination an electric magnetic field employed to minimize effect secondary electrons. The authors first investigate these approaches beam energies 70, 150, 230 250 MeV, fields between 0 24 mT voltages -1000 1000 V. When applying...