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1.
Support Care Cancer ; 32(7): 470, 2024 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-38951291

RESUMO

PURPOSE: This study aimed to compare the effects of a mobile health intervention based on social cognitive theory with standard care on maximal mouth opening, exercise compliance, and self-efficacy in patients receiving proton and heavy ion therapy for head and neck cancer. METHODS: This open-label, parallel-group, randomized, superiority trial involved a self-developed "Health Enjoy System" intervention. We assessed maximal mouth opening, exercise compliance, and self-efficacy at baseline (T0), post-treatment (T1), and at 1 month (T2) and 3 months (T3) after radiotherapy. Generalized estimating equations were used to analyze differences between the groups over time, with results reported as P values and 95% confidence intervals (CIs). RESULTS: The study included 44 participants. At T3, the intervention group showed a 6 mm greater increase in maximal interincisal opening than the control group (mean difference = 6.0, 95% CI = 2.4 to 9.5, P = 0.001). There was also a significant difference in exercise compliance between the groups (mean difference = 31.7, 95% CI = 4.6 to 58.8, P = 0.022). However, no significant difference in self-efficacy was found between the groups. CONCLUSION: This study demonstrated that an mHealth intervention incorporating behavior change theory could effectively enhance or maintain maximal mouth opening in patients undergoing proton and heavy ion therapy for head and neck cancer in China. This approach provides valuable support during and after treatment. TRIAL REGISTRATION: ChiCTR: ChiCTR2300067550. Registered 11 Jan 2023.


Assuntos
Neoplasias de Cabeça e Pescoço , Terapia com Prótons , Autoeficácia , Telemedicina , Trismo , Humanos , Neoplasias de Cabeça e Pescoço/radioterapia , Neoplasias de Cabeça e Pescoço/complicações , Neoplasias de Cabeça e Pescoço/terapia , Masculino , Pessoa de Meia-Idade , Feminino , Terapia com Prótons/métodos , Trismo/etiologia , Trismo/terapia , Radioterapia com Íons Pesados/métodos , Terapia por Exercício/métodos , Idoso , Cooperação do Paciente/estatística & dados numéricos , Adulto
2.
J Radiol Prot ; 44(2)2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38834051

RESUMO

The measurement of linear energy transfer (LET) is crucial for the evaluation of the radiation effect in heavy ion therapy. As two detectors which are convenient to implant into the phantom, the performance of CR-39 and thermoluminescence detector (TLD) for LET measurement was compared by experiment and simulation in this study. The results confirmed the applicability of both detectors for LET measurements, but also revealed that the CR-39 detector would lead to potential overestimation of dose-averaged LET compared with the simulation by PHITS, while the TLD would have a large uncertainty measuring ions with LET larger than 20 keVµm-1. The results of this study were expected to improve the detection method of LET for therapeutic carbon beam and would finally be benefit to the quality assurance of heavy ion radiotherapy.


Assuntos
Radioterapia com Íons Pesados , Transferência Linear de Energia , Dosimetria Termoluminescente , Dosimetria Termoluminescente/instrumentação , Imagens de Fantasmas , Carbono , Desenho de Equipamento , Polietilenoglicóis
3.
J Radiat Res ; 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38940734

RESUMO

The ionizing radiation with high linear energy transfer (LET), such as a heavy ion beam, induces more serious biological effects than low LET ones, such as gamma- and X-rays. This indicates a difference in the DNA damage produced by low and high LET radiations and their biological effects. We have been studying the differences in DNA damage produced by gamma-rays and carbon ion beams. Therefore, we analyze mutations induced by both ionizing radiations to discuss the differences in their biological effects in this study. pUC19 plasmid DNA was irradiated by carbon ion beams in the solution containing 1M dimethyl sulfoxide to mimic a cellular condition. The irradiated DNA was cloned in competent cells of Escherichia coli. The clones harboring some mutations in the region of lacZα were selected, and the sequence alterations were analyzed. A one-deletion mutation is significant in the carbon-irradiated DNA, and the C:G↔T:A transition is minor. On the other hand, the gamma-irradiated DNA shows mainly G:C↔T:A transversion. These results suggest that carbon ion beams produce complex DNA damage, and gamma-rays are prone to single oxidative base damage, such as 8-oxoguanine. Carbon ion beams can also introduce oxidative base damage, and the damage species is 5-hydroxycytosine. This was consistent with our previous results of DNA damage caused by heavy ion beams. We confirmed the causal DNA damage by mass spectrometry for these mutations.

4.
J Radiat Res ; 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38924483

RESUMO

In the next decade, the International Commission on Radiological Protection (ICRP) will issue the next set of general recommendations, for which evaluation of relative biological effectiveness (RBE) for various types of tissue reactions would be needed. ICRP has recently classified diseases of the circulatory system (DCS) as a tissue reaction, but has not recommended RBE for DCS. We therefore evaluated the mean and uncertainty of RBE for DCS by applying a microdosimetric kinetic model specialized for RBE estimation of tissue reactions. For this purpose, we analyzed several RBE data for DCS determined by past animal experiments and evaluated the radius of the subnuclear domain best fit to each experiment as a single free parameter included in the model. Our analysis suggested that RBE for DCS tends to be lower than that for skin reactions, and their difference was borderline significant due to large variances of the evaluated parameters. We also found that RBE for DCS following mono-energetic neutron irradiation of the human body is much lower than that for skin reactions, particularly at the thermal energy and around 1 MeV. This tendency is considered attributable not only to the intrinsic difference of neutron RBE between skin reactions and DCS but also to the difference in the contributions of secondary γ-rays to the total absorbed doses between their target organs. These findings will help determine RBE by ICRP for preventing tissue reactions.

5.
Bioresour Technol ; 406: 130965, 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38876280

RESUMO

Microalgae's superior ability to fix carbon dioxide into biomass and high-value bioproducts remains underutilized in biotechnological applications due to a lack of comprehensive understanding of their carbon metabolism and energy conversion. In this work, the strain improvement technique heavy-ion beams (HIB) mutagenesis was employed on the environmentally adaptable microalgae Scenedesmus quadricauda. After several rounds of screening, two contrasting mutants were identified. S-#4 showed low photosynthetic activity and biomass productivity, while S-#26 exhibited adaptability to prolonged high light stress, achieving a 28.34 % increase in biomass yield compared to the wild-type strain. Integrating their photosynthetic characteristics and comparative proteomic analysis revealed that the contrasting protein regulations from central carbon metabolism mainly affects the two mutants' opposite biomass accumulation. Therefore, the divergent regulation of the tricarboxylic acid cycle following HIB mutagenesis could be potential targets for engineering microalgae with superior biomass and high-value products.

6.
Front Plant Sci ; 15: 1352564, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38693931

RESUMO

Heavy-ion beam, a type of ionizing radiation, has been applied to plant breeding as a powerful mutagen and is a promising tool to induce large deletions and chromosomal rearrangements. The effectiveness of heavy-ion irradiation can be explained by linear energy transfer (LET; keV µm-1). Heavy-ion beams with different LET values induce different types and sizes of mutations. It has been suggested that deletion size increases with increasing LET value, and complex chromosomal rearrangements are induced in higher LET radiations. In this study, we mapped heavy-ion beam-induced deletions detected in Arabidopsis mutants to its genome. We revealed that deletion sizes were similar between different LETs (100 to 290 keV µm-1), that their upper limit was affected by the distribution of essential genes, and that the detected chromosomal rearrangements avoid disrupting the essential genes. We also focused on tandemly arrayed genes (TAGs), where two or more homologous genes are adjacent to one another in the genome. Our results suggested that 100 keV µm-1 of LET is enough to disrupt TAGs and that the distribution of essential genes strongly affects the heritability of mutations overlapping them. Our results provide a genomic view of large deletion inductions in the Arabidopsis genome.

7.
Sci Rep ; 14(1): 7643, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38561390

RESUMO

Semiconductor devices used in radiation environment are more prone to degradation in device performance. Junctionless Tunnel Field Effect Transistor (JLTFET) is one of the most potential candidates which overcomes the short channel effects and fabrication difficulties. In this work, 20 nm JLTFET is proposed with Silicon in the drain/channel region whereas source uses different materials, Silicon Germanium (SiGe), Gallium Nitride (GaN), Gallium Arsenide (GaAs), Indium Arsenide (InAs). The device performance is examined by subjecting it to heavy ion radiation at a lower and higher dose of linear energy transfer (LET) values. It can be seen that the most sensitive location is the source/channel (S/C) interface for SiGe, GaN and GaAs whereas the drain/channel (D/C) interface for InAs. Further analysis is carried out at these vulnerable regions by matching ION of all materials. The parameters, transient peak current (Ipeak), collected charge (QC), threshold voltage shift (ΔVth) and bipolar gain (ß) are extracted using transient simulations. It is observed that for a lower dose of LET, Ipeak of SiGe is 27% lesser than InAs and for higher dose of LET, SiGe shows 56% lesser Ipeak than InAs. SiGe is less sensitive at lower and higher dose of LET due to reduced ΔVth, tunneling and electron density.

8.
Materials (Basel) ; 17(3)2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38591410

RESUMO

Natural monoclinic zirconia (baddeleyite) was irradiated with 340 MeV Au ions, and the irradiation-induced nanostructures (i.e., ion tracks and nanohillocks) were observed using transmission electron microscopy. The diameter of the nanohillocks was approximately 10 nm, which was similar to the maximum molten region size calculated using the analytical thermal spike model. Ion tracks were imaged as strained regions that maintained their crystalline structure. The cross-sections of most of the ion tracks were imaged as rectangular contrasts as large as 10 nm. These results strongly indicated that the molten region was recrystallized anisotropically, reflecting the lattice structure. Furthermore, low-density track cores were formed in the center of the ion tracks. The formation of low-density track cores can be attributed to the ejection of molten matter toward the surface. A comparison of the ion tracks in the synthetic zirconia nanoparticles and those in larger natural zirconia samples showed that the interface between the strained track contrast and the matrix was less clear in the former than in the latter. These findings suggest that the recrystallization process was affected by the size of the irradiated samples.

9.
Bioresour Technol ; 400: 130648, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38561153

RESUMO

Open unsterile fermentation of the low-cost non-food crop, sweet sorghum, is an economically feasible lactic acid biosynthesis process. However, hyperosmotic stress inhibits microbial metabolism and lactic acid biosynthesis, and engineering strains with high osmotic tolerance is challenging. Herein, heavy ion mutagenesis combined with osmotic pressure enrichment was used to engineer a hyperosmotic-tolerant Bacillus coagulans for L-lactic acid production. The engineered strain had higher osmotic pressure tolerance, when compared with the parental strain, primarily owing to its improved properties such as cell viability, cellular antioxidant capacity, and NADH supply. In a pilot-scale open unsterile fermentation using sweet sorghum juice as a feedstock, the engineered strain produced 94 g/L L-lactic acid with a yield of 91 % and productivity of 6.7 g/L/h, and optical purity of L-lactic acid at the end of fermentation was 99.8 %. In short, this study provided effective and low-cost approach to produce polymer-grade L-lactic acid.


Assuntos
Bacillus coagulans , Fermentação , Ácido Láctico , Pressão Osmótica , Sorghum , Ácido Láctico/biossíntese , Ácido Láctico/metabolismo , Sorghum/metabolismo
10.
J Liver Cancer ; 24(1): 33-46, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38523467

RESUMO

This review examines the transformative role of external beam radiotherapy (EBRT) in managing hepatocellular carcinoma (HCC), spotlighting the progression from traditional EBRT techniques to advanced modalities like intensity-modulated radiotherapy (RT), stereotactic body RT (SBRT), and innovative particle therapy, including proton beam therapy and carbon ion RT. These advancements have significantly improved the precision and efficacy of RT, marking a paradigm shift in the multimodal management of HCC, particularly in addressing complex cases and enhancing local tumor control. The review underscores the synergistic potential of integrating RT with other treatments like transarterial chemoembolization, systemic therapies such as sorafenib, and emerging immunotherapies, illustrating enhanced survival and disease control outcomes. The efficacy of RT is addressed for challenging conditions, including advanced HCC with macrovascular invasion, and RT modalities, like SBRT, are compared against traditional treatments like radiofrequency ablation for early-stage HCC. Additionally, the review accentuates the encouraging outcomes of particle therapy in enhancing local control and survival rates, minimizing treatment-related toxicity, and advocating for continued research and clinical trials. In conclusion, the integration of RT into multimodal HCC treatment strategies, coupled with the emergence of particle therapy, is crucial for advancing oncologic management, emphasizing the need for relentless innovation and personalized treatment approaches.

12.
Cancer ; 130(14): 2528-2537, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38373062

RESUMO

INTRODUCTION: This study aims to quantitatively assess eligible patients and project the demand for particle therapy facilities in India from 2020 to 2040. In addition, an economic analysis evaluates the financial feasibility of implementing this technology. The study also examines the prospective benefits and challenges of adopting this technology in India. METHODOLOGY: Cancer incidence and projected trends were analyzed for pediatric patients using the Global Childhood Cancer microsimulation model and adult patients using the Globocan data. Economic cost evaluation is performed for large-scale combined particle (carbon and proton-three room fixed-beam), large-scale proton (one gantry and two fixed-beam), and small-scale proton (one gantry) facility. RESULTS: By 2040, the estimated number of eligible patients for particle therapy is projected to reach 161,000, including approximately 14,000 pediatric cases. The demand for particle therapy facilities is projected to rise from 81 to 97 in 2020 to 121 to 146 by 2040. The capital expenditure is estimated to be only 3.7 times that of a standard photon linear accelerator over a 30-year period. Notably, the treatment cost can be reduced to USD 400 to 800 per fraction, substantially lower than that in high-income countries (USD 1000 to 3000 per fraction). CONCLUSION: This study indicates that, in the Indian scenario, all particle therapy models are cost-beneficial and feasible, with large-scale proton therapy being the most suitable. Despite challenges such as limited resources, space, a skilled workforce, referral systems, and patient affordability, it offers substantial benefits. These include the potential to treat many patients and convenient construction and operational costs. An iterative phased implementation strategy can effectively overcome these challenges, paving the way for the successful adoption of particle therapy in India. PLAIN LANGUAGE SUMMARY: In India, the number of eligible patients benefiting from high-precision particle therapy technology is projected to rise till 2040. Despite high upfront costs, our study finds the long-term feasibility of all particle therapy models, potentially offering a substantial reduction in treatment cost compared to high-income countries. Despite challenges, India can succeed with an iterative phased approach.


Assuntos
Neoplasias , Humanos , Índia/epidemiologia , Neoplasias/terapia , Neoplasias/economia , Neoplasias/radioterapia , Neoplasias/epidemiologia , Criança , Terapia com Prótons/economia , Adulto , Necessidades e Demandas de Serviços de Saúde/economia , Análise Custo-Benefício
13.
Entropy (Basel) ; 26(2)2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38392422

RESUMO

We investigate the effects of boost invariance breaking on the isotropization of pressure in the glasma, using a 3+1D glasma simulation. The breaking is attributed to spatial fluctuations in the classical color charge density along the collision axis. We present numerical results for pressure and energy density at mid-rapidity and across a wider rapidity region. It is found that, despite varying longitudinal correlation lengths, the behaviors of the pressure isotropizations are qualitatively similar. The numerical results suggest that, in the initial stage, longitudinal color electromagnetic fields develop, similar to those in the boost invariant glasma. Subsequently, these fields evolve into a dilute glasma, expanding longitudinally in a manner akin to a dilute gas. We also show that the energy density at mid-rapidity exhibits a 1/τ decay in the dilute glasma stage.

14.
Plant Reprod ; 2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38332356

RESUMO

KEY MESSAGE: In Cyrtanthus mackenii, development of embryo and endosperm were differentially affected by fertilization of male gametes with DNA damage and mutations. Pollen irradiation with ionizing radiations has been applied in plant breeding and genetic research, and haploid plant induction has mainly been performed by male inactivation with high-dose irradiation. However, the fertilization process of irradiated male gametes and the early development of embryo and endosperm have not received much attention. Heavy-ion beams, a type of radiation, have been widely applied as effective mutagens for plants and show a high mutation rate even at low-dose irradiation. In this study, we analyzed the effects of male gametes of Cyrtanthus mackenii irradiated with a carbon-ion beam at low doses on fertilization. In immature seeds derived from the pollination of irradiated pollen grains, two types of embryo sacs were observed: embryo sac with a normally developed embryo and endosperm and embryo sac with an egg cell or an undivided zygote and an endosperm. Abnormalities in chromosome segregation, such as chromosomal bridges, were observed only in the endosperm nuclei, irrespective of the presence or absence of embryogenesis. Therefore, in Cyrtanthus, embryogenesis is strongly affected by DNA damage or mutations in male gametes. Moreover, various DNA contents were detected in the embryo and endosperm nuclei, and endoreduplication may have occurred in the endosperm nuclei. As carbon-ion irradiation causes chromosomal rearrangements even at low doses, pollen irradiation can be an interesting tool for studying double fertilization and mutation heritability.

15.
Cancers (Basel) ; 16(4)2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38398109

RESUMO

BACKGROUND: The current study aims to evaluate the occurrence of temporal lobe reactions and identify possible risk factors for patients who underwent particle therapy of the skull base. METHODS: 244 patients treated for skull base chordoma (n = 144) or chondrosarcoma (n = 100) at the Heidelberg Ion Beam Therapy Center (HIT) using a raster scan technique, were analyzed. Follow-up MRI-scans were matched with the initial planning images. Radiogenic reactions were contoured and analyzed based on volume and dose of treatment. RESULTS: 51 patients with chordoma (35.4%) and 30 patients (30%) with chondrosarcoma experienced at least one temporal lobe reaction within the follow-up period (median 49 months for chondrosarcoma, 62 months for chordoma). Age, irradiated volume, and dose values were significant risk factors for the development of temporal lobe reactions with the highest significance for the value of DMax-7 being defined as the dose maximum in the temporal lobe minus the 7cc with the highest dose (p = 0.000000000019; OR 1.087). CONCLUSION: Temporal lobe reactions are a common side effect after particle therapy of the skull base. We were able to develop a multivariate model, which predicted radiation reactions with a specificity of 99% and a sensitivity of 52.2%.

16.
Micromachines (Basel) ; 15(2)2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38398958

RESUMO

This paper thoroughly analyses the role of drift in the sensitive region in the single-event effect (SEE), with the aim of enhancing the single-particle radiation resistance of N-type metal-oxide semiconductor field-effect transistors (MOSFETs). It proposes a design for a Si-based device structure that extends the lightly doped source-drain region of the N-channel metal-oxide semiconductor (NMOS), thereby moderating the electric field of the sensitive region. This design leads to a 15.69% decrease in the charge collected at the leaky end of the device under the standard irradiation conditions. On this basis, a device structure is further proposed to form a composite metal-oxide semiconductor (MOS) by connecting a pn junction at the lightly doped source-drain end. By adding two charge paths, the leakage collection charge is further reduced by 13.85% under standard irradiation conditions. Moreover, the deterioration of the drive current in the purely growing lightly doped source-drain region can be further improved. Simulations of single-event effects under different irradiation conditions show that the device has good resistance to single-event irradiation, and the composite MOS structure smoothly converges to a 14.65% reduction in drain collection charge between 0.2 pC/µm and 1 pC/µm Linear Energy Transfer (LET) values. The incidence position at the source-to-channel interface collects the highest charge reduction rate of 28.23%. The collecting charge reduction rate is maximum, at 17.12%, when the incidence is at a 45-degree angle towards the source.

17.
Materials (Basel) ; 17(4)2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38399150

RESUMO

Graphite IG-110 is a synthetic polycrystalline material used as a neutron moderator in reactors. Graphite is inherently brittle and is known to exhibit a further increase in brittleness due to radiation damage at room temperature. To understand the irradiation effects on pre-existing defects and their overall influence on external load, micropillar compression tests were performed using in situ nanoindentation in the Transmission Electron Microscopy (TEM) for both pristine and ion-irradiated samples. While pristine specimens showed brittle and subsequent catastrophic failure, the 2.8 MeV Au2+ ion (fluence of 4.378 × 1014 cm-2) irradiated specimens sustained extensive plasticity at room temperature without failure. In situ TEM characterization showed nucleation of nanoscale kink band structures at numerous sites, where the localized plasticity appeared to close the defects and cracks while allowing large average strain. We propose that compressive mechanical stress due to dimensional change during ion irradiation transforms buckled basal layers in graphite into kink bands. The externally applied load during the micropillar tests proliferates the nucleation and motion of kink bands to accommodate the large plastic strain. The inherent non-uniformity of graphite microstructure promotes such strain localization, making kink bands the predominant mechanism behind unprecedented toughness in an otherwise brittle material.

18.
Sensors (Basel) ; 24(4)2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38400223

RESUMO

In the pursuit of enhancing the technological maturity of innovative magnetic sensing techniques, opportunities presented by in-orbit platforms (IOD/IOV experiments) provide a means to evaluate their in-flight capabilities. The Magnetic Experiments for the Laser Interferometer Space Antenna (MELISA) represent a set of in-flight demonstrators designed to characterize the low-frequency noise performance of a magnetic measurement system within a challenging space environment. In Low Earth Orbit (LEO) satellites, electronic circuits are exposed to high levels of radiation coming from energetic particles trapped by the Earth's magnetic field, solar flares, and galactic cosmic rays. A significant effect is the accidental bit-flipping in memory registers. This work presents an analysis of memory data redundancy resources using auxiliary second flash memory and exposes recovery options to retain critical data utilizing a duplicated data structure. A new and lightweight technique, CCM (Cross-Checking and Mirroring), is proposed to verify the proper performance of these techniques. Four alternative algorithms included in the original version of the MELISA software (Version v0.0) are presented. All the versions have been validated and evaluated according to various merit indicators. The evaluations showed similar performances for the proposed techniques, and they are valid for situations in which the flash memory suffers from more than one bit-flip. The overhead due to the introduction of additional instructions to the main code is negligible, even in the target experiment based on an 8-bit microcontroller.

19.
Phys Med Biol ; 69(4)2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38232394

RESUMO

Objective. Helium, oxygen, and neon ions in addition to carbon ions will be used for hypofractionated multi-ion therapy to maximize the therapeutic effectiveness of charged-particle therapy. To use new ions in cancer treatments based on the dose-fractionation protocols established in carbon-ion therapy, this study examined the cell-line-specific radioresponse to therapeutic helium-, oxygen-, and neon-ion beams within wide dose ranges.Approach. Response of cells to ions was described by the stochastic microdosimetric kinetic model. First, simulations were made for the irradiation of one-field spread-out Bragg peak beams in water with helium, carbon, oxygen, and neon ions to achieve uniform survival fractions at 37%, 10%, and 1% for human salivary gland tumor (HSG) cells, the reference cell line for the Japanese relative biological effectiveness weighted dose system, within the target region defined at depths from 90 to 150 mm. The HSG cells were then replaced by other cell lines with different radioresponses to evaluate differences in the biological dose distributions of each ion beam with respect to those of carbon-ion beams.Main results. For oxygen- and neon-ion beams, the biological dose distributions within the target region were almost equivalent to those of carbon-ion beams, differing by less than 5% in most cases. In contrast, for helium-ion beams, the biological dose distributions within the target region were largely different from those of carbon-ion beams, more than 10% in several cases.Significance.From the standpoint of tumor control evaluated by the clonogenic cell survival, this study suggests that the dose-fractionation protocols established in carbon-ion therapy could be reasonably applied to oxygen- and neon-ion beams while some modifications in dose prescription would be needed when the protocols are applied to helium-ion beams. This study bridges the gap between carbon-ion therapy and hypofractionated multi-ion therapy.


Assuntos
Carbono , Hélio , Humanos , Neônio/uso terapêutico , Carbono/uso terapêutico , Hélio/uso terapêutico , Oxigênio/uso terapêutico , Íons , Eficiência Biológica Relativa
20.
Asia Pac J Clin Oncol ; 20(2): 240-250, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36683266

RESUMO

BACKGROUND: Proton and carbon-ion therapy may spare normal tissues in regions with many critical structures surrounding the target volume. As toxicity outcome data are emerging, we aimed to synthesize the published data for the toxicity outcomes of proton or carbon-ion therapy (together known as particle beam therapy [PBT]) for primary nasopharyngeal carcinoma (NPC). MATERIALS AND METHODS: We searched PubMed and Scopus electronic databases to identify original studies reporting toxicity outcomes following PBT of primary NPC. Quality assessment was performed using NIH's Quality Assessment Tool. Reports were extracted for information on demographics, main results, and clinical and dose factors correlates. Meta-analysis was performed using the random-effects model. RESULTS: Twelve studies were selected (six using mixed particle-photon beams, five performed comparisons to photon-based therapy). The pooled event rates for acute grade ≥2 toxicities mucositis, dermatitis, xerostomia weight loss are 46% (95% confidence interval [95% CI]-29%-64%, I2 = 87%), 47% (95% CI-28%-67%, I2 = 87%), 16% (95% CI-9%-29%, I2 = 76%), and 36% (95% CI-27%-47%, I2 = 45%), respectively. Only one late endpoint (xerostomia grade ≥2) has sufficient data for analysis with pooled event rate of 9% (95% CI-3%-29%, I2 = 77%), lower than intensity-modulated radiotherapy 27% (95% CI-10%-54%, I2 = 95%). For most endpoints with significant differences between the PBT and photon-based therapies, PBT resulted in better outcomes. In two studies where dose distribution was studied, doses to the organs at risk were independent risk factors for toxicities. CONCLUSION: PBT may reduce the risk of acute toxicities for patients treated for primary NPC, likely due to dose reduction to critical structures. The pooled event rate for toxicities derived in this study can be a guide for patient counseling.


Assuntos
Neoplasias Nasofaríngeas , Terapia com Prótons , Radioterapia de Intensidade Modulada , Xerostomia , Humanos , Prótons , Carcinoma Nasofaríngeo/radioterapia , Terapia com Prótons/efeitos adversos , Terapia com Prótons/métodos , Seguimentos , Xerostomia/etiologia , Neoplasias Nasofaríngeas/patologia , Carbono , Radioterapia de Intensidade Modulada/métodos
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