Classical Radiation Research Articles

The Influence of the Microbiome on the Complications of Radiotherapy and Its Effectiveness in Patients with Laryngeal Cancer.

Radiotherapy is an effective method of treating cancer and affects 50% of patients. Intensity-modulated radiotherapy (IMRT) is a modernized method of classical radiation used in the treatment of laryngeal cancer. Treatment with intent to preserve the larynx is not always safe or complication-free. The microbiome may significantly influence the effectiveness of oncological treatment, especially radiotherapy, and may also be modified by the toxic response to radiation. The aim of the study was to prospectively assess the microbiome and its influence on radiotherapy toxicity in patients with laryngeal cancer. Statistically significant risk factors for complications after radiotherapy were the percentage of Porphyromonas of at least 6.7%, the percentage of Fusobacterium of at least 2.6% and the percentage of Catonella of at least 2.6%. The importance of the microbiome in oncology has been confirmed in many studies. Effective radiotherapy treatment and the prevention of radiation-induced oral mucositis is a challenge in oncology. The microbiome may be an important part of personalized cancer treatment. The assessment of the microbiome of patients diagnosed with cancer may provide the opportunity to predict the response to treatment and its effectiveness. The influence of the microbiome may be important in predicting the risk group for radiotherapy treatment failure. The possibility of modifying the microbiome may become a goal to improve the prognosis of patients with laryngeal cancer. Fusobacterium, Porphyromonas and Catonella are important risk factors for radiation-induced oral mucositis in patients with laryngeal cancer.

Classicalization of Quantum Mechanics: Classical Radiation Damping Without the Runaway Solution

In this paper, we review a new treatment of classical radiation damping, which resolves a known contradiction in the Abraham–Lorentz equation that has long been a concern. This radiation damping problem has already been solved in quantum mechanics by the method introduced by Friedrichs. Based on Friedrichs’ treatment, we solved this long-standing problem by classicalizing quantum mechanics by replacing the canonical commutation relation from quantum mechanics with the Poisson bracket relation in classical mechanics.

Classical acceleration temperature (CAT) in a box

A confined, non-relativistic, accelerating electron is shown to emit thermal radiation. Since laboratories face spatial constraints when dealing with rectilinear motion, focusing on a finite total travel distance combines the benefits of simple theoretical analysis with prospects for table-top experimentation. We demonstrate an accelerated moving charge along an asymptotically static worldline with fixed transit distance and non-relativistic maximum speed, emitting self-consistent analytic power, spectra, and energy. The classical radiation is Planck distributed with an associated acceleration temperature. This is the first fully parametrized, spectrum-solved, finite-distance worldline.

Narrative review on efficacy and safety of anti-angiogenesis in combination with immunotherapy in the treatment of breast cancer.

Breast cancer was the second frequently diagnosed cancer in 2022 among all cancers. Besides classical chemotherapy and radiation, immunotherapy and targeted therapy are both identical treatment options for patients with advanced breast cancer. Immunotherapy is a therapeutic approach to control and eliminate tumors by restarting and maintaining the tumor-immunity cycle and restoring the body's normal anti-tumor immune response. Immunotherapy alone or in combination with other therapies has been shown to be clinically beneficial in a variety of solid tumors with a manageable safety profile. However, immunotherapy alone cannot fully satisfy the therapeutic needs for patients with breast cancer. Therefore, there is an urgent need for immunotherapy to be combined with other therapeutic approaches to increase treatment efficacy. We systematically searched PubMed database for relevant studies published over the past 5 years. Articles were screened for eligibility and key data extracted. We assess the current breast cancer treatment landscape, summarizing efficacy and safety of recent immunotherapy, chemotherapy combined with immunotherapy, immunotherapy combined with anti-angiogenic therapy. In the treatment of breast cancer, aiming to promote further research and applications of this novel treatment regimen in patients with breast cancer. Since anti-angiogenic therapy can reprogramme the tumor immune microenvironment, immunotherapy in combination with anti-angiogenic therapy might have a synergistic effect, igniting a new hope for immunotherapy for breast cancer patients. The review's conclusions offer insightful information on the state of breast cancer treatment today. In the end, improving clinical practice and pertinent research for immunotherapy combination therapy will contribute to bettering patient outcomes, raising quality of life, and creating more potent treatments. This review emphasizes the potential of immunotherapy combinations, especially with anti-angiogenic therapeutic regimens, as a viable strategy for the treatment of breast cancer through a thorough study of the literature. To improve treatment approaches, lessen side effects for patients, and find trustworthy biomarkers to forecast response to immunotherapy combo medicines, further research is necessary.

Semiclassical solution of black hole information paradox

Abstract We resolve black hole information paradox within semiclassical gravity, in a manner that does not depend on details of unknown quantum gravity. Our crucial insight is that outgoing Hawking particles are physical only far from the black hole horizon, so they are created far from the horizon and entangled with degrees of freedom closer to the horizon. The latter degrees of freedom can be understood as quasi-classical coherent states, implying that Hawking radiation is accompanied with additional radiation similar to classical radiation by which the black hole loses hair during the classical gravitational collapse. The two kinds of radiation are entangled, which resolves black hole information paradox.

Radiation and reaction at one loop

We study classical radiation fields at next-to-leading order using the methods of scattering amplitudes. The fields of interest to us are sourced when two massive, point-like objects scatter inelastically, and can be computed from one-loop amplitudes. The real and imaginary parts of the amplitudes play important but physically distinct roles in the radiation field. We argue that the imaginary part captures the effects of radiation reaction. This aspect of radiation reaction is directly linked to cuts of one-loop amplitudes which expose Compton trees. We also discuss the fascinating interplay between renormalisation, radiation reaction and classical field theory from this perspective.

Genomic evidence reveals three W-autosome fusions in Heliconius butterflies.

Sex chromosomes are evolutionarily labile in many animals and sometimes fuse with autosomes, creating so-called neo-sex chromosomes. Fusions between sex chromosomes and autosomes have been proposed to reduce sexual conflict and to promote adaptation and reproductive isolation among species. Recently, advances in genomics have fuelled the discovery of such fusions across the tree of life. Here, we discovered multiple fusions leading to neo-sex chromosomes in the sapho subclade of the classical adaptive radiation of Heliconius butterflies. Heliconius butterflies generally have 21 chromosomes with very high synteny. However, the five Heliconius species in the sapho subclade show large variation in chromosome number ranging from 21 to 60. We find that the W chromosome is fused with chromosome 4 in all of them. Two sister species pairs show subsequent fusions between the W and chromosomes 9 or 14, respectively. These fusions between autosomes and sex chromosomes make Heliconius butterflies an ideal system for studying the role of neo-sex chromosomes in adaptive radiations and the degeneration of sex chromosomes over time. Our findings emphasize the capability of short-read resequencing to detect genomic signatures of fusion events between sex chromosomes and autosomes even when sex chromosomes are not explicitly assembled.

Unified lattice Boltzmann framework for coupled non-Fourier conduction and thermal radiation based on the C-V model

This research enhances our previously established unified lattice Boltzmann (LB) framework, initially developed for classical Fourier heat conduction and radiation coupling, to now adeptly handle non-Fourier heat conduction and thermal radiation transfer at the micro and nanoscale. It effectively manages the disparities in propagation speeds and complex transient boundary conditions. Validation against one-dimensional benchmarks confirms its accuracy and reliability. The study also examines the influence of critical parameters like the radiative heat transfer parameter Nc, scattering albedo, and optical thickness on thermal dynamics. Significantly, it provides a quantitative error analysis of the steady-state radiation assumption in coupled problems, revealing its limitations under various conditions. This enhanced framework represents a solid improvement in micro and nanoscale multiphysics simulations using the lattice Boltzmann method, ensuring a balance between computational precision and efficiency. It contributes to the development of more refined thermal management strategies in diverse industrial and scientific applications.

Anthropogenic Impacts in the Lower Stratosphere: Scale Invariant Analysis

Aircraft and rockets entered the lower stratosphere on a regular basis during World War II and have done so in increasing numbers to the present. Atmospheric testing of nuclear weapons saw radioactive isotopes in the stratosphere. Rocket launches of orbiters are projected to increase substantially in the near future. The burnup of orbiters has left signatures in the aerosol. There are proposals to attenuate incoming solar radiation by deliberate injection of artificial aerosols into the stratosphere to “geoengineer” cooling trends in surface temperature, with the aim of countering the heating effects of infrared active gases. These gases are mainly carbon dioxide from fossil burning, with additional contributions from methane, chlorofluorocarbons, nitrous oxide and the accompanying positive feedback from increasing water vapor. Residence times as a function of altitude above the tropopause are critical. The analysis of in situ data is performed using statistical multifractal techniques and combined with remotely sensed and modeled results to examine the classical radiation–photochemistry–fluid mechanics interaction that determines the composition and dynamics of the lower stratosphere. It is critical in assessing anthropogenic effects. It is argued that progress in predictive ability is driven by the continued generation of new and quantitative observations in the laboratory and the atmosphere.

Co-relation of Portal Vein Tumour Thrombus Response With Survival Function Following Robotic Radiosurgery in Vascular Invasive Hepatocellular Carcinoma

Purpose or ObjectiveProspective evaluation of stereotactic body radiotherapy (SBRT) with Robotic Radiosurgery in hepatocellular carcinoma patients with macrovascular invasion (HCC-PVT). Materials and MethodsPatients with inoperable HCC-PVT, good performance score (PS0-1) and preserved liver function (up to Child Pugh B7) were accrued after ethical and scientific committee approval [CTRI: 2022/01/050234] for treatment on Robotic Radiosurgery (M6) and planned with Multiplan (iDMS V2.0). Triple-phase contrast computed tomography (CT) scan was done for contouring and gross tumor volume (GTV) included contrast enhancing mass within main portal vein and adjacent parenchymal disease. Dose prescription was as per risk stratification protocol (22- 50Gy in 5 fractions) while achieving the constraints of mean liver dose <15Gy, 800 cc liver <8Gy and the duodenum max of <24 Gy). Response assessment done at 2 months follow up for recanalization. Patient and treatment related factors evaluated for influence in survival function. ResultsBetween Jan 2017 till May 2022, 317 consecutive HCC with PVT patients were screened and 219 patients were accrued [male 92%, CP score 5-7 90%, mean age 63 years (38-85yrs), CLIP <3: 84 (40%), 3-6 117 (56%), infective etiology 9.5%, Performance status (PS) 0-37%; 1-56%]. Among 209 consecutive patients after accrual SBRT treatment done (10 patients were excluded after accrual due to ascites and decompensation), 139 were evaluable for response assessment (>2 mo follow up). At mean follow up of 10.2 months (SD 8.43), 88 (63%) patients expired and 51 (36%) were alive. 82 (59%) patients had recanalization of PVT (response), 57 (41%) pts did not recanalize, 28 (17%) had progressive disease had progressive/metastatic disease prior to response evaluation (<2 months). Mean overall survival in responders and non-responders were 18.4 (SE 2.52) and 9.34 month (SE 0.81) respectively (p<0.001). Mean survival in patients with PS0, PS1 and PS2 were 17, 11.7 and 9.7 months (p- 0.019) respectively. Overall survival (OS) in partial recanalization, bland thrombus and complete recanalization was 12.4, 14.1, 30.3 months respectively (p-0.002). Adjuvant sorafenib, Barcelona Clinic Liver Classification (BCLC) stage, gender, age, RT dose did not influence response to treatment. Recanalization rate was higher in good PS patients (p-0.019). OS in patients with response to treatment, no response to treatment, fit but not accrued and not suitable patients were 18.4, 9.34, 5.9, 2.6 months respectively (p-<0.001). 36/139 patients (24%) had RILD [10 (7.2%) had Classic Radiation induced liver disease (RILD) & 26 (19%) had non-classic RILD]. Derangement in Child Pugh Score (CP score change) by more than 2 was seen in 30 (24%) within 2-month period after Robotic Radiosurgery. 18 (13%) had unplanned admissions, two patients required embolization due to fiducial related bleeding, 20 (14%) had ascites of which 9 (6%) patients required abdominocentesis. ConclusionPVT response or recanalization after SBRT is a statistically significant prognostic factor for survival function in HCC-PVT.

Thermal Larmor Radiation

Abstract Thermal radiation is found from a moving point charge along a special, globally defined, continuous accelerated trajectory. The calculation is entirely classical (despite the appearance of ℏ) but is shown to have an immediate connection to quantum field theory via the moving mirror model. A precise recipe is given for the functional mathematical identity of the electron–mirror duality that allows one to map between (1) the classical radiation of an ordinary accelerating point charge in 3+1 Minkowski spacetime and (2) the quantum radiation of a moving mirror in 1+1 flat spacetime, for a given rectilinear trajectory.

The Puzzling of Stefan–Boltzmann Law: Classical or Quantum Physics

Stefan–Boltzmann law, stating the fourth power temperature dependence of the radiation emission by a black-body, was empirically formulated by Stefan in 1874 by fitting existing experiments and theoretically validated by Boltzmann in 1884 on the basis of a classical physical model involving thermodynamics principles and the radiation pressure predicted by Maxwell equations. At first sight the electromagnetic (EM) gas assumed by Boltzmann and following Rayleigh (1900) identifiable as an ensemble of N classical normal-modes, looks like an extension of the classical model of the massive ideal-gas. Accordingly, for this EM gas the internal total energy, U, was assumed to be function of volume V and temperature T as [Formula: see text], and the equation of state was given by [Formula: see text], with P the radiation pressure. In addition, Boltzmann implicitly assumed that, for given values of V and T, U and the number of modes N would take finite values. However, from one hand these assumptions are not justified by Maxwell equations and classical statistics since, in vacuum (i.e., far from the EM sources), the values of N and U diverge, the so-called ultraviolet catastrophe introduced by Ehrenfest in 1911. From another hand, Boltzmann derivation of Stefan law is found to be macroscopically compatible with its derivation from quantum statistics announced by Planck in 1901. In this paper, we present a justification of this puzzling classical/quantum compatibility by noticing that the implicit assumptions made by Boltzmann is fully justified by Planck quantum statistics. Furthermore, we shed new light on the interpretation of recent classical simulations of a black body carried out by Wang, Casati, and Benenti in 2022 who found an analogous puzzling consistency between Stefan–Boltzmann law and their simulations to induce speculations on classical physics and black body radiation that are claimed to require a critical reconsideration of the role of classical physics for the understanding of quantum mechanics.

Analytical solutions for quantum radiation reaction in high-intensity lasers

While the Landau-Lifshitz equation, which describes classical radiation reaction, can be solved exactly and analytically for a charged particle accelerated by a plane electromagnetic wave, no such solutions are available for quantum radiation reaction (the recoil arising from the successive, incoherent emission of hard photons). Yet upcoming experiments with ultrarelativistic electron beams and high-intensity lasers will explore the regime where both radiation-reaction and quantum effects are important. Here we present analytical solutions for the mean and variance of the energy distribution of an electron beam that collides with a pulsed plane electromagnetic wave, which are obtained by means of a perturbative expansion in the quantum parameter χ0. These solutions capture both the quantum reduction in the radiated power and the stochastic broadening, and are shown to be accurate across the range of experimentally relevant collision parameters, i.e., GeV-class electron beams and laser amplitudes a0≲200. Published by the American Physical Society 2024

High dose proton and photon-based radiation therapy for 213 liver lesions: a multi-institutional dosimetric comparison with a clinical perspective

BackgroundStereotactic radiotherapy (SRT) and Proton therapy (PT) are both options in the management of liver lesions. Limited clinical-dosimetric comparison are available. Moreover, dose-constraint routinely used in liver PT and SRT considers only the liver spared, while optimization strategies to limit the liver damaged are poorly reported.MethodsPrimary endpoint was to assess and compare liver sparing of four contemporary RT techniques. Secondary endpoints were freedom from local recurrence (FFLR), overall survival (OS), acute and late toxicity. We hypothesize that Focal Liver Reaction (FLR) is determined by a similar biologic dose. FLR was delineated on follow-up MRI. Mean C.I. was computed for all the schedules used. A so-called Fall-off Volume (FOV) was defined as the area of healthy liver (liver-PTV) receiving more than the isotoxic dose. Fall-off Volume Ratio (FOVR) was defined as ratio between FOV and PTV.Results213 lesions were identified. Mean best fitting isodose (isotoxic doses) for FLR were 18Gy, 21.5 Gy and 28.5 Gy for 3, 5 and 15 fractions. Among photons, an advantage in terms of healthy liver sparing was found for Vmat FFF with 5mm jaws (p = 0.013) and Cyberknife (p = 0.03). FOV and FOVR resulted lower for PT (p < 0.001). Three years FFLR resulted 83%. Classic Radiation induced liver disease (RILD, any grade) affected 2 patients.ConclusionsCyberknife and V-MAT FFF with 5mm jaws spare more liver than V-MAT FF with 10 mm jaws. PT spare more liver compared to photons. FOV and FOVR allows a quantitative analysis of healthy tissue sparing performance showing also the quality of plan in terms of dose fall-off.

Enhanced Classical Radiation Damping of Electronic Cyclotron Motion in the Vicinity of the Van Hove Singularity in a Waveguide

Abstract We study the damping process of electron cyclotron motion and the resulting emission in a waveguide using the classical Friedrichs model without relying on perturbation analysis such as Fermi’s golden rule. A Van Hove singularity appears at the lower bound (or cutoff frequency) of the dispersion associated with each of the electromagnetic field modes in the waveguide. In the vicinity of the Van Hove singularity, we found that not only is the decay process associated with the resonance pole enhanced (amplification factor ∼104) but the branch-point effect is also comparably enhanced. As a result, the timescale on which most of the decay occurs is dramatically shortened. Further, this suggests that the non-Markovian branch-point effect should be experimentally observable in the vicinity of the Van Hove singularity. Our treatment yields a physically acceptable solution without the problematic runaway solution that is well known to appear in the traditional treatment of classical radiation damping based on the Abraham–Lorentz equation.

The field theory of collective Cherenkov radiation associated with electron beams

Classical Cherenkov radiation is a celebrated physics phenomenon of electromagnetic (EM) radiation stimulated by an electric charge moving with constant velocity in a three-dimensional dielectric medium. Cherenkov radiation has a wide spectrum and a particular distribution in space similar to the Mach cone created by a supersonic source. It is also characterized by the energy transfer from the charge's kinetic energy to the EM radiation. In the case of an electron beam passing through the middle of an EM waveguide, the radiation is manifested as collective Cherenkov radiation. In this case, the electron beam can be viewed as a one-dimensional non-neutral plasma, whereas the waveguide can be viewed as a slow wave structure. This collective radiation occurs, in particular, in traveling wave tubes (TWTs), and it features the energy transfer from the electron beam to the EM radiation in the waveguide. Based on a first principles Lagrangian field theory, we develop a convincing argument that the collective Cherenkov effect in TWTs is, in fact, a convective instability, that is, amplification. We also recover Pierce's theory as a high-frequency limit of our generalized Lagrangian theory. Finally, we derive for the first time expressions identifying low- and high-frequency cutoffs for amplification in TWTs.

Classical Larmor formula through the Unruh effect for uniformly accelerated electrons

We investigate the connection between the classical Larmor formula and the quantum Unruh effect by computing the emitted power by a uniformly accelerated charged particle and its angular distribution in the coaccelerated frame. We consider a classical particle accelerated with nonzero charge only for a finite period and then take the infinite-time limit after removing the effects due to the initial charging and final discharging processes. We show that the result found for the interaction rates agrees with previous studies in which the period of acceleration with nonzero charge was taken to be infinite from the beginning. We also show that the power and angular distribution of emission, which is attributed either to the emission or absorption of a Rindler photon in the coaccelerated frame, is given by the Larmor formula, confirming that, at tree level, it is necessary to take into account the Unruh effect in order to reproduce the classical Larmor radiation formula in the coaccelerated frame. Published by the American Physical Society 2024

Classical radiation fields for scalar, electromagnetic, and gravitational waves with spacetime-symmetry breaking

An effective field theory framework is used to investigate some Lorentz-violating effects on the generation of electromagnetic and gravitational waves, complementing previous work on propagation. Specifically we find solutions to a modified, anisotropic wave equation, sourced by charge or fluid matter. We derive the radiation fields for scalars, classical electromagnetic radiation, and partial results for gravitational radiation. For gravitational waves, the results show longitudinal and breathing polarizations proportional to coefficients for spacetime-symmetry breaking.

Perturbative soft photon theorems in de Sitter spacetime

We define a perturbative S-matrix in a local patch of de Sitter background in the limit when the curvature length scale (ℓ) is large and study the ‘soft’ behavior of the scalar QED amplitudes in de Sitter spacetime in generic dimensions. We obtain the leading and subleading perturbative corrections to flat space soft photon theorems in the large ℓ limit, and comment on the universality of these corrections. We compare our results with the electromagnetic memory tails obtained earlier in d = 4 using classical radiation analysis.

Radiotherapy for Advanced Esophageal Cancer: from Palliation to Curation.

Esophageal cancer is a global health problem, which is 7th most common and 6th most deadly cancer. It has been the era of immuno-oncology for esophageal cancer management. Radiation therapy has been one of the key local therapeutic approaches for esophageal cancer treatment, while its role in advanced disease is challenging and debatable. There have been emerging clinical and translational studies of radiation therapy in recurrent or metastatic esophageal cancer. Immunotherapy has been established the standard care of 1st and 2nd line systemic therapies of advanced esophageal cancer, and the development of tumor immunity has opened a new chapter for the esophageal cancer radiation therapy. The current review will summarize the classic radiation therapy research in advanced esophageal cancer, as well as the most recent key findings. The subtitles will cover palliative radiotherapy for dysphagia, re-radiation for recurrent disease, oligo-focal disease management and stereotactic radiation therapy, and radiotherapy with immunotherapy. Radiotherapy plays vital role in multidisciplinary management of advanced EC. External or intratumoral irradiation has been used for palliation of dysphagia and improving QOL in esophageal cancer patients traditionally, while recent clinical and technical advance enables radiotherapy to be considered in recurrent or metastatic disease for curation attention. Novel clinical and translational investigation is opening a new chapter of radiotherapy with immunotherapy for benefiting advanced EC patients.