Characterization of scintillator crystals for usage as prompt gamma monitors in particle therapy
K. RoemerG. PauschD. BemmererM. BerthelA. DreyerC. GolnikF. Hueso-GonzálezT. KormollJ. PetzoldtH. RohlingP. G. ThirolfA. WagnerLouis K. WagnerD. WeinbergerF. Fiedler
15
Citation
59
Reference
10
Related Paper
Citation Trend
Abstract:
Particle therapy in oncology is advantageous compared to classical radiotherapy due to its well-defined penetration depth. In the so-called Bragg peak, the highest dose is deposited; the tissue behind the cancerous area is not exposed. Different factors influence the range of the particle and thus the target area, e.g. organ motion, mispositioning of the patient or anatomical changes. In order to avoid over-exposure of healthy tissue and under-dosage of cancerous regions, the penetration depth of the particle has to be monitored, preferably already during the ongoing therapy session. The verification of the ion range can be performed using prompt gamma emissions, which are produced by interactions between projectile and tissue, and originate from the same location and time of the nuclear reaction. The prompt gamma emission profile and the clinically relevant penetration depth are correlated. Various imaging concepts based on the detection of prompt gamma rays are currently discussed: collimated systems with counting detectors, Compton cameras with (at least) two detector planes, or the prompt gamma timing method, utilizing the particle time-of-flight within the body. For each concept, the detection system must meet special requirements regarding energy, time, and spatial resolution. Nonetheless, the prerequisites remain the same: the gamma energy region (2 to 10 MeV), high counting rates and the stability in strong background radiation fields. The aim of this work is the comparison of different scintillation crystals regarding energy and time resolution for optimized prompt gamma detection.Keywords:
Collimated light
Particle Therapy
Particle detector
Heavy-particle therapy such as carbon ion therapy are more popular nowadays because of the nature characteristics of charged particle and almost no side effect to patients. An effective treatment is achieved with high precision of dose calculation, in this research work, Geant4 based Monte Carlo simulation method has been used to calculate the radiation transport and dose distribution. The simulation have the same setting with the treatment room in Heavy Ion Medical Accelerator, HIMAC. The carbon ion beam at the isocentric gantry nozzle for the therapeutic energy of 290 MeV/u was simulated, experimental work was carried out in National Institute of Radiological Sciences, NIRS, Chiba, Japan by using the HIMAC to confirm the accuracy and qualities dose distribution by MC methods. The Geant4 based simulated dose distribution were verified with measurements for Bragg peak and spread out Bragg peak (SOBP) respectively. The verification of results shows that the Bragg peak depth-dose and SOBP distributions in simulation has good agreement with measurements. In overall, the study showed that Geant4 based can be fully applied in the heavy-ion therapy field for simulation, further works need to be carry on to refine and improve the Geant4 MC simulations.
Sobp
Particle Therapy
Carbon Ion Radiotherapy
Cite
Citations (2)
Particle Therapy
Linear energy transfer
Particle radiation
Base of skull
Cite
Citations (170)
Due to the high LET and dense ionisation tracks associated with ions, microdosimetric approaches have been used in carbon ion therapy to assess field quality and calculate radiobiological quantities for a variety of cell lines. There is however a lack of instrumentation for simple and routine use in a clinical environment, important for determination of RBE which provides accurate treatment planning and delivery in hadron therapy. In this study, a 10 μm thick silicon microdosimeter with 3D sensitive volumes has been used to investigate the effect of motion on the RBE and field quality of a typical 12C ion therapy beam. For a passively scattered 290 MeV/u 12C beam with 6 cm spread-out Bragg peak (SOBP), variations in biological dose along the SOBP were observed, as well as a significant changes to particle LET when incident on a moving target.
Sobp
Particle Therapy
Relative biological effectiveness
Cite
Citations (5)
The scintillation index on the axis for Gaussian beams focused and collimated in weak marine turbulence is formulated via the usage of Rytov method. The average bit error rate <BER> is evaluated using this formulation. The scintillation index and <BER> versus propagation distance and source size are determined by using the log-normal distributed. Intensity for the collimated and focused. Gaussian beams, which are exhibited for wavelength, source size, focal length, and <SNR>. The focused beams are revealing more advantageous than collimated beams in an atmospheric marine environment. The findings of this study are significant for optical communication system performance in this layer.
Collimated light
Gaussian beam
Intensity
Cite
Citations (3)
Charted-particle therapy (CPT) benefits cancer patients by localizing doses in the tumor volume while minimizing the doses delivered to normal tissue through its unique physical and biological characteristics. The world's first CPT applied on humans was proton beam therapy (PBT), which was performed in the mid-1950s. Among heavy ions, carbon ions showed the most favorable biological characteristics for the treatment of cancer patients. Carbon ions show coincidence between the Bragg peak and maximum value of relative biological effectiveness. In addition, they show low oxygen enhancement ratios. Therefore, carbon-ion radiotherapy (CIRT) has become mainstream in the treatment of cancer patients using heavy ions. CIRT was first performed in 1977 at the Lawrence Berkeley Laboratory. The CPT technology has advanced in the intervening decades, enabling the use of rotating gantry, beam delivery with fast pencil-beam scanning, image-guided particle therapy, and intensity-modulated particle therapy. As a result, as of 2019, a total of 222,425 and 34,138 patients with cancer had been treated globally with PBT and CIRT, respectively. For more effective and efficient CPT, many groups are currently conducting further studies worldwide. This review summarizes recent technological advances that facilitate clinical use of CPT.
Particle Therapy
Relative biological effectiveness
Cancer Therapy
Pencil-beam scanning
Carbon Ion Radiotherapy
Cancer Treatment
Cite
Citations (11)
The introduction of 'new' ion species in particle therapy needs to be supported by a thorough assessment of their dosimetric properties and by treatment planning comparisons with clinically used proton and carbon ion beams. In addition to the latter two ions, helium and oxygen ion beams are foreseen at the Heidelberg Ion Beam Therapy Center (HIT) as potential assets for improving clinical outcomes in the near future. We present in this study a dosimetric validation of a FLUKA-based Monte Carlo treatment planning tool (MCTP) for protons, helium, carbon and oxygen ions for spread-out Bragg peaks in water. The comparisons between the ions show the dosimetric advantages of helium and heavier ion beams in terms of their distal and lateral fall-offs with respect to protons, reducing the lateral size of the region receiving 50% of the planned dose up to 12 mm. However, carbon and oxygen ions showed significant doses beyond the target due to the higher fragmentation tail compared to lighter ions (p and He), up to 25%. The Monte Carlo predictions were found to be in excellent geometrical agreement with the measurements, with deviations below 1 mm for all parameters investigated such as target and lateral size as well as distal fall-offs. Measured and simulated absolute dose values agreed within about 2.5% on the overall dose distributions. The MCTP tool, which supports the usage of multiple state-of-the-art relative biological effectiveness models, will provide a solid engine for treatment planning comparisons at HIT.
Particle Therapy
Pencil-beam scanning
Relative biological effectiveness
Cite
Citations (48)
Positron emission tomography (PET) is currently the only feasible method for in-situ and noninvasive three-dimensional monitoring of the precision of the treatment in highly conformal ion therapy. Its positive clinical impact has been proven for fractionated carbon ion therapy of head and neck (H&N) tumors at the experimental facility at the Gesellschaft fur Schwerionenforschung (GSI), Darmstadt, Germany. Following previous promising experiments, the possible extension of the method to the monitoring of proton therapy has been investigated further in extensive in-beam measurements at GSI. Millimeter accuracy for verification of the lateral field position and for the most challenging issue of range monitoring has been demonstrated in monoenergetic and spread-out Bragg-peak (SOBP) proton irradiation of polymethyl methacrylate (PMMA) targets. The irradiation of an inhomogeneous phantom with tissue equivalent inserts in combination with further dynamic analysis has supported the extension of such millimeter precision to real clinical cases, at least in regions of interest for low perfused tissues. All the experimental investigations have been reproduced by the developed modeling rather well. This indicates the possible extraction of valuable clinical information as particle range in-vivo, irradiation field position, and even local deviations from the dose prescription on the basis of the comparison between measured and predicted activity distributions. Hence, the clinical feasibility of in-beam PET for proton therapy monitoring is strongly supported.
Sobp
Particle Therapy
Cite
Citations (125)
Particle Therapy
Relative biological effectiveness
Particle beam
Particle (ecology)
Cite
Citations (0)
Background: Numerous qualitative studies have been carried out on the safety and clinical use of GNPs as a radio-sensitizer in tumors, using proton therapy and the results have been promising. However, some quantitative studies should be conducted in order to examine the factors affecting this method. Methods: Monte Carlo simulation was performed by MCNPX code to assess pristine Bragg peak, spread-out bragg peak (SOBP), and secondary particle production enhancement in GNPs radio-sensitized tumor using proton therapy. Results: The results show several percent dose enhancement within and its reduction after the tumor site. A little increase in neutron production and no deviation for photon production is indicated. Conclusions: Finally, it can be concluded that sensitization of a realistic tumor can be beneficial during the proton therapy.
Sobp
Particle Therapy
Cite
Citations (5)
Lateral response heterogeneity of Bragg peak ionization chambers was measured by Kuess et al (2017) using collimated x-rays. It is argued in this comment that the laterally extended low dose tails of the collimated x-rays should be accurately measured and included in the study.
Collimated light
Cite
Citations (4)