FLASH Bragg-Peak Irradiation With a Therapeutic Carbon Ion Beam: First In Vivo Results.

Purpose: In recent years, ultra-high dose rate (UHDR) irradiation has emerged as a promising innovative approach to cancer treatment. Characteristic feature of this regimen, commonly referred to as FLASH effect, demonstrated primarily for electrons, photons, or protons, is the improved normal tissue sparing, whereas the tumor control is similar to the one of the conventional dose-rate (CDR) treatments. The FLASH mechanism is, however, unknown.

Imaging lung tumor motion using integrated-mode proton radiography-A phantom study towards tumor tracking in proton radiotherapy.

Background: Motion of lung tumors during radiotherapy leads to decreased accuracy of the delivered dose distribution. This is especially true for proton radiotherapy due to the finite range of the proton beam. Methods for mitigating motion rely on knowing the position of the tumor during treatment.

A Fast 3D Range-Modulator Delivery Approach: Validation of the FLUKA Model on a Varian ProBeam System Including a Robustness Analysis.

A 3D range-modulator (RM), optimized for a single energy and a specific target shape, is a promising and viable solution for the ultra-fast dose delivery in particle therapy. The aim of this work was to investigate the impact of potential beam and modulator misalignments on the dose distribution. Moreover, the FLUKA Monte Carlo model, capable of simulating 3D RMs, was adjusted and validated for the 250 MeV single-energy proton irradiation from a Varian ProBeam system.

Influenza Virus Inactivated by Heavy Ion Beam Irradiation Stimulates Antigen-Specific Immune Responses.

The COVID-19 pandemic has made clear the need for effective and rapid vaccine development methods. Conventional inactivated virus vaccines, together with new technologies like vector and mRNA vaccines, were the first to be rolled out. However, the traditional methods used for virus inactivation can affect surface-exposed antigen, thereby reducing vaccine efficacy.

Development of porous structure for broadening Bragg-peak in scanning carbon-ion radiotherapy: Monte Carlo simulation and experimental validation.

Purpose: The present study aimed to develop a porous structure with plug-ins (PSP) to broaden the Bragg peak width (BPW, defined as the distance in water between the proximal and distal 80% dose) of the carbon ion beam while maintaining a sharp distal falloff width (DFW, defined as the distance along the beam axis where the dose in water reduces from 80% to 20%).

Methods: The binary voxel models of porous structure (PS) and PSP were established in the Monte Carlo code FLUKA and the corresponding physical models were manufactured by 3D printing. Both experiment and simulation were performed for evaluating the modulation capacity of PS and PSP.

Ground-based passive generation of Solar Particle Event spectra: Planning and manufacturing of a 3D-printed modulator.

The generation of space radiation on Earth is essential to study and predict the effects of radiation on space travelers, electronics, or materials during future long-term space missions. Next to the heavy ions of the galactic cosmic rays, solar particle events play a major role concerning the radiation risk in space, which consist of intermediate-energy protons with broad spectra and energies up to a few hundred MeV. This work describes an approach for the ground-based generation of solar particle events.

Quasi-real-time range monitoring by in-beam PET: a case for O.

A fast and reliable range monitoring method is required to take full advantage of the high linear energy transfer provided by therapeutic ion beams like carbon and oxygen while minimizing damage to healthy tissue due to range uncertainties. Quasi-real-time range monitoring using in-beam positron emission tomography (PET) with therapeutic beams of positron-emitters of carbon and oxygen is a promising approach. The number of implanted ions and the time required for an unambiguous range verification are decisive factors for choosing a candidate isotope.

Production and separation of positron emitters for hadron therapy at FRS-Cave M.

The FRagment Separator FRS at GSI is a versatile spectrometer and separator for experiments with relativistic in-flight separated short-lived exotic beams. One branch of the FRS is connected to the target hall where the bio-medical cave (Cave M) is located. Recently a joint activity between the experimental groups of the FRS and the biophysics at the GSI and Department of physics at LMU was started to perform biomedical experiments relevant for hadron therapy with positron emitting carbon and oxygen beams.

Precision of the PET activity range during irradiation withC,C, andC beams.

. Beams of stable ions have been a well-established tool for radiotherapy for many decades. In the case of ion beam therapy with stableC ions, the positron emittersC are produced via projectile and target fragmentation, and their decays enable visualization of the beam via positron emission tomography (PET).

Reduction of recombination effects in large plane parallel beam monitors for FLASH radiotherapy with scanned ion beams.

Purpose: Radiotherapy escalating dose rates above 50Gys, might offer a great potential in treating tumours while further sparing healthy tissue. However, these ultra-high intensities of FLASH-RT lead to new challenges with regard to dosimetry and beam monitoring. FLASH experiments at HIT (Heidelberg Ion Beam Therapy Center) and at GSI (GSI Helmholtz Centre for Heavy Ion Research) have shown a significant loss of signal in the beam monitoring system due to recombination effects.

Depth dose measurements in water for C and C beams with therapy relevant energies.

Owing to the favorable depth-dose distribution and the radiobiological properties of heavy ion radiation, ion beam therapy shows an improved success/toxicity ratio compared to conventional radiotherapy. The sharp dose gradients and very high doses in the Bragg peak region, which represent the larger physical advantage of ion beam therapy, make it also extremely sensitive to range uncertainties. The use of -radioactive ion beams would be ideal for simultaneous treatment and accurate online range monitoring through PET imaging.

Dose Attenuation in Innovative Shielding Materials for Radiation Protection in Space: Measurements and Simulations.

Galactic cosmic rays (GCR) are among the main deterrents to manned space exploration. Currently, the most realistic way to reduce the dangers caused by GCR to acceptable levels is passive shielding. Light materials guarantee the strongest dose attenuation per unit mass.

FLASH with carbon ions: Tumor control, normal tissue sparing, and distal metastasis in a mouse osteosarcoma model.

Background And Purpose: The FLASH effect is a potential breakthrough in radiotherapy because ultra-high dose-rate irradiation can substantially widen the therapeutic window. While the normal tissue sparing at high doses and short irradiation times has been demonstrated with electrons, photons, and protons, so far evidence with heavy ions is limited to in vitro cell experiments. Here we present the first in vivo results with high-energy C-ions delivered at an ultra-high dose rate.

Thick shielding against galactic cosmic radiation: A Monte Carlo study with focus on the role of secondary neutrons.

The exposure to galactic cosmic radiation (GCR) is a major health concern for astronauts. Crewed missions with durations of several years are foreseen in future space exploration projects such as permanent habitats on the Moon and flights to Mars. This aim requires elaborate space radiation shielding concepts and a proper understanding of the underlying radiation physics and radiobiology as well as their interplay.

Experimental Comparison of Fiducial Markers Used in Proton Therapy: Study of Different Imaging Modalities and Proton Fluence Perturbations Measured With CMOS Pixel Sensors.

Fiducial markers are used for image guidance to verify the correct positioning of the target for the case of tumors that can suffer interfractional motion during proton therapy. The markers should be visible on daily imaging, but at the same time, they should produce minimal streak artifacts in the CT scans for treatment planning and induce only slight dose perturbations during particle therapy. In this work, these three criteria were experimentally investigated at the Heidelberg Ion Beam Therapy Center.

Roadmap: helium ion therapy.

Helium ion beam therapy for the treatment of cancer was one of several developed and studied particle treatments in the 1950s, leading to clinical trials beginning in 1975 at the Lawrence Berkeley National Laboratory. The trial shutdown was followed by decades of research and clinical silence on the topic while proton and carbon ion therapy made debuts at research facilities and academic hospitals worldwide. The lack of progression in understanding the principle facets of helium ion beam therapy in terms of physics, biological and clinical findings persists today, mainly attributable to its highly limited availability.

Development, Monte Carlo simulations and experimental evaluation of a 3D range-modulator for a complex target in scanned proton therapy.

The purpose of this work was to develop and manufacture a 3D range-modulator (3D RM) for a complex target contour for scanned proton therapy. The 3D RM is considered to be a viable technique for the very fast dose application in patient-specific tumors with only one fixed energy. The RM was developed based on a tumor from a patient CT and manufactured with high-quality 3D printing techniques with both polymer resin and aluminum.

Ultra-High Dose Rate (FLASH) Carbon Ion Irradiation: Dosimetry and First Cell Experiments.

Purpose: To establish a beam monitoring and dosimetry system to enable the FLASH dose rate carbon ion irradiation and investigate, at different oxygen concentrations, the in vitro biological response in comparison to the conventional dose rate.

Methods And Materials: CHO-K1 cell response to irradiation at different dose rates and at different levels of oxygenation was studied using clonogenic assay. The Heidelberg Ion-Beam Therapy Center (HIT) synchrotron, after technical improvements, was adjusted to extract ≥5 × 10C ions within approximately 150 milliseconds.

Radioactive Beams for Image-Guided Particle Therapy: The BARB Experiment at GSI.

Several techniques are under development for image-guidance in particle therapy. Positron (β) emission tomography (PET) is in use since many years, because accelerated ions generate positron-emitting isotopes by nuclear fragmentation in the human body. In heavy ion therapy, a major part of the PET signals is produced by β-emitters generated projectile fragmentation.

Interaction of therapeuticC ions with bone-like targets: physical characterization and dosimetric effect at material interfaces.

Carbon therapy is a promising treatment option for cancer. The physical and biological properties of carbon ions can theoretically allow for the delivery of curative doses to the tumor, while simultaneously limiting risks of toxicity to adjacent healthy structures. The treatment effectiveness can be further improved by decreasing the uncertainties stemming from several sources, including the modeling of tissue heterogeneity.

Physical characterization ofHe ion beams for radiotherapy and comparison withHe.

There is increasing interest in using helium ions for radiotherapy, complementary to protons and carbon ions. A large number of patients were treated withHe ions in the US heavy ion therapy project and novelHe ion treatment programs are under preparation, for instance in Germany and Japan.He ions have been proposed as an alternative toHe ions because the acceleration ofHe is technically less difficult thanHe.

Technical note: Vendor-agnostic water phantom for 3D dosimetry of complex fields in particle therapy.

Purpose: Three-dimensional (3D) dosimetry is a necessity to validate patient-specific treatment plans in particle therapy as well as to facilitate the development of novel treatment modalities. Therefore, a vendor-agnostic water phantom was developed and verified to measure high resolution 3D dose distributions.

Methods: The system was experimentally validated at the Marburger Ionenstrahl-Therapiezentrum using two ionization chamber array detectors (PTW Octavius 1500XDR and 1000P) with 150.

Monte Carlo simulations and dose measurements of 2D range-modulators for scanned particle therapy.

This paper introduces the concept of a 2D range-modulator as a static device for generating spread-out Bragg peaks at very small distances to the target. The 2D range-modulator has some distinct advantages that can be highly useful for different research projects in particle therapy facilities. Most importantly, it creates an instantaneous, quasi-static irradiation field with only one energy, thus decreasing irradiation time tremendously.

Fluence perturbation from fiducial markers due to edge-scattering measured with pixel sensors for C ion beams.

Fiducial markers are nowadays a common tool for patient positioning verification before radiotherapy treatment. These markers should be visible on x-ray projection imaging, produce low streak artifacts on CTs and induce small dose perturbations due to edge-scattering effects during the ion-beam therapy treatment. In this study, the latter effect was investigated and the perturbations created by the markers were evaluated with a new measurement method using a tracker system composed of six CMOS pixel sensors.